Patent Publication Number: US-10765508-B2

Title: Ocular mask having selective spectral transmission

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 15/809,581, filed Nov. 10, 2017, which is a continuation of U.S. patent application Ser. No. 15/377,891, now U.S. Pat. No. 9,848,979, filed Dec. 13, 2016, which is a continuation of U.S. patent application Ser. No. 13/691,625, now U.S. Pat. No. 9,545,303, filed Nov. 30, 2012, which claims priority benefit of U.S. Provisional Application Ser. No. 61/566,523, filed Dec. 2, 2011, the entire contents of which are hereby incorporated by reference. 
    
    
     BACKGROUND 
     Field 
     This application relates generally to the field of ocular devices. For example, this application is directed to ocular devices with an aperture to improve depth of focus (e.g. “masked” corneal inlays) and methods of making. 
     Description of the Related Art 
     The human eye functions to provide vision by transmitting and focusing light through a clear outer portion called the cornea, and further refining the focus of the image by way of a crystalline lens onto a retina. The quality of the focused image depends on many factors including the size and shape of the eye, and the transparency of the cornea and the lens. 
     The optical power of the eye is determined by the optical power of the cornea and the crystalline lens. In a normal, healthy eye, sharp images of distant objects are formed on the retina (emmetropia). In many eyes, images of distant objects are either formed in front of the retina because the eye is abnormally long or the cornea is abnormally steep (myopia), or formed in back of the retina because the eye is abnormally short or the cornea is abnormally flat (hyperopia). The cornea also may be asymmetric or toric, resulting in an uncompensated cylindrical refractive error referred to as corneal astigmatism. 
     A normally functioning human eye is capable of selectively focusing on either near or far objects through a process known as accommodation. Accommodation is achieved by inducing deformation in the natural crystalline lens located inside the eye. Such deformation is induced by muscles called ciliary muscles. In most individuals, the ability to accommodate diminishes with age and these individuals cannot see up close without vision correction. If far vision also is deficient, such individuals are usually prescribed bifocal lenses. 
     SUMMARY 
     A first aspect of this application is directed toward an ophthalmic device comprising 
     a mask configured to increase the depth of focus of a patient. The mask comprising an aperture configured to transmit along an optical axis substantially all visible incident light. The mask further comprising a structure surrounding the aperture. The structure configured to be substantially opaque to visible light and to be substantially transparent to at least some non-visible electromagnetic radiation with a wavelength between about 750 nm and about 1500 nm. 
     Another aspect of this application is directed toward an ophthalmic device configured to increase the depth of focus of a patient. The ophthalmic device includes a first zone configured to transmit along an optical axis a majority of visible incident light, and a mask disposed about the first zone and being configured to be substantially opaque to visible light and to be substantially transparent to at least some electromagnetic radiation outside of the visible spectrum. 
     In any of the aspects of the ophthalmic device, the mask is substantially transparent to at least some electromagnetic radiation in the near infrared spectrum. 
     In any of the aspects of the ophthalmic device, the ophthalmic device includes a plurality of holes in the structure. The plurality of holes are interspersed in an irregular pattern and configured to permit a bond to form between lens body portions on either side of the mask. 
     In any of the above mentioned aspects of the ophthalmic device, each of the plurality of holes has a diameter between about 0.01 mm and 0.02 mm. 
     In any of the above mentioned aspects of the ophthalmic device, the structure includes at least one dye capable of absorbing electromagnetic radiation. 
     In any of the above mentioned aspects of the ophthalmic device, the at least one dye includes a first dye and a second dye. The first dye absorbs a first range of electromagnetic radiation wavelengths, and the second dye absorbs a second range of electromagnetic radiation wavelengths. 
     In any of the above mentioned aspects of the ophthalmic device, the first range of electromagnetic radiation wavelengths and the second range of electromagnetic radiation wavelengths include substantially all the range of visible electromagnetic radiation thereby absorbing substantially all the range of visible electromagnetic radiation. The first range of electromagnetic radiation wavelengths and the second range of electromagnetic radiation wavelengths do not include a substantial range of the near infrared range of electromagnetic radiation thereby allowing transmission of substantially all the range of near infrared electromagnetic radiation. 
     In any of the above mentioned aspects of the ophthalmic device, the at least one dye includes a third dye. The third dye absorbs a third range of electromagnetic radiation wavelengths. 
     In any of the above mentioned aspects of the ophthalmic device, the first range of electromagnetic radiation wavelengths, the second range of electromagnetic radiation wavelengths, and the third range of electromagnetic radiation wavelengths include substantially all the range of visible electromagnetic radiation thereby absorbing substantially all the range of visible electromagnetic radiation. The first range of electromagnetic radiation wavelengths, the second range of electromagnetic radiation wavelengths, and the third range of electromagnetic radiation wavelengths do not include a substantial range of the near infrared range of electromagnetic radiation thereby allowing transmission of substantially all the range of near infrared electromagnetic radiation. 
     In any of the above mentioned aspects of the ophthalmic device, the first dye is an orange dye and wherein the second dye is a blue-green dye. 
     In any of the above mentioned aspects of the ophthalmic device, the first dye is an orange dye, the second dye is a blue-green dye, and the third dye is a yellow dye. 
     In any of the above mentioned aspects of the ophthalmic device, the orange dye is 2-[N-ethyl-4-[(4-nitrophenyl)diazenyl]anilino]ethyl prop-2-enoate. 
     In any of the above mentioned aspects of the ophthalmic device, the blue-green dye is 2-[4-({4-[(4-{2-[(2-methylprop-2-enoyl)oxy]ethyl}phenyl)amino]-9,10-dioxo-9,10-dihydro-anthracen-1-yl}amino)phenyl]ethyl-2-methyl prop-2-enoate 
     In any of the above mentioned aspects of the ophthalmic device, the ophthalmic device includes a UV blocker. The UV blocker blocks at least some of the UV range of electromagnetic radiation. 
     In any of the above mentioned aspects of the ophthalmic device, the UV blocker is a benzotriazole UV blocker. 
     In any of the above mentioned aspects of the ophthalmic device, the UV blocker is ([2-(5-Chloro-2H-Benzotriazole-2-yl)-6-(1,1-dimethylethyl)-4-ethenylphenol. 
     In any of the above mentioned aspects of the ophthalmic device, the ophthalmic device includes a UV blocker. The UV blocker is ([2-(5-Chloro-2H-Benzotriazole-2-yl)-6-(1,1-dimethylethyl)-4-ethenylphenol. The at least one dye includes 2-[N-ethyl-4-[(4-nitrophenyl)diazenyl]anilino]ethyl prop-2-enoate and 2-[4-({4-[(4-{2-[(2-methylprop-2-enoyl)oxy]ethyl}phenyl)amino]-9,10-dioxo-9,10-dihydro-anthracen-1-yl}amino)phenyl]ethyl-2-methyl prop-2-enoate. 
     Another aspect of this application is directed toward a method of examining an eye of a patient having a pinhole imaging device disposed therein. The method includes aligning a source of electromagnetic radiation with a portion of the pinhole imaging device that is substantially non-transmissive to light in the visible range and transmitting electromagnetic radiation with a wavelength between about 750 nm and about 1500 nm through the substantially non-transmissive portion. 
     In any of the above mentioned aspect of the method of examining an eye, the method includes providing an optical coherence tomography device having a patient interface and engaging the patient with the patient interface. 
     In any of the above mentioned aspect of the method of examining an eye, the method includes transmitting electromagnetic radiation with a wavelength between about 750 nm and about 1500 nm through the aperture of the pinhole imaging device. 
     In any of the above mentioned aspect of the method of examining an eye, the method includes the electromagnetic radiation is simultaneously transmitted through the aperture and the substantially non-transmissive portion of the pinhole imaging device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plan view of the human eye. 
         FIG. 2  is a cross-sectional side view of the human eye. 
         FIG. 3  is a cross-sectional side view of the human eye of a presbyopic patient wherein the light rays converge at a point behind the retina of the eye. 
         FIG. 4  is a cross-sectional side view of a presbyopic eye implanted with one embodiment of a mask wherein the light rays converge at a point on the retina. 
         FIG. 5  is a plan view of the human eye with a mask applied thereto. 
         FIG. 6  is a perspective view of one embodiment of a mask. 
         FIG. 7  is a frontal plan view of an embodiment of a mask with a hexagon-shaped pinhole like aperture. 
         FIG. 8  is a frontal plan view of an embodiment of a mask with an octagon-shaped pinhole like aperture. 
         FIG. 9  is a frontal plan view of an embodiment of a mask with an oval-shaped pinhole like aperture. 
         FIG. 10  is a frontal plan view of an embodiment of a mask with a pointed oval-shaped pinhole like aperture. 
         FIG. 11  is a frontal plan view of an embodiment of a mask with a star-shaped pinhole like aperture. 
         FIG. 12  is a frontal plan view of an embodiment of a mask with a teardrop-shaped pinhole like aperture spaced above the true center of the mask. 
         FIG. 13  is a frontal plan view of an embodiment of a mask with a teardrop-shaped pinhole like aperture centered within the mask. 
         FIG. 14  is a frontal plan view of an embodiment of a mask with a teardrop-shaped pinhole like aperture spaced below the true center of the mask. 
         FIG. 15  is a frontal plan view of an embodiment of a mask with a square-shaped pinhole like aperture. 
         FIG. 16  is a frontal plan view of an embodiment of a mask with a kidney-shaped oval pinhole like aperture. 
         FIG. 17  is a side view of an embodiment of a mask having varying thickness. 
         FIG. 18  is a side view of another embodiment of a mask having varying thickness. 
         FIG. 19  is a side view of an embodiment of a mask with a gel to provide opacity to the lens. 
         FIG. 20  is a frontal plan view of an embodiment of a mask with a weave of polymeric fibers. 
         FIG. 21  is a side view of the mask of  FIG. 20 . 
         FIG. 22  is a frontal plan view of an embodiment of a mask having regions of varying opacity. 
         FIG. 23  is a side view of the mask of  FIG. 22 . 
         FIG. 24  is a frontal plan view of an embodiment of a mask that includes a centrally located pinhole like aperture and radially extending slots emanating from the center to the periphery of the mask. 
         FIG. 25  is a side view of the mask of  FIG. 24 . 
         FIG. 26  is a frontal plan view of an embodiment of a mask that includes a central pinhole like aperture, surrounded by a plurality of holes radially spaced from the pinhole like aperture and slots extending radially spaced from the holes and extending to the periphery of the mask. 
         FIG. 27  is a side view of the mask of  FIG. 26 . 
         FIG. 28  is a frontal plan view of an embodiment of a mask that includes a central pinhole like aperture, a region that includes a plurality of holes radially spaced from the aperture, and a region that includes rectangular slots spaced radially from the holes. 
         FIG. 29  is a side view of the mask of  FIG. 28 . 
         FIG. 30  is a frontal plan view of an embodiment of a mask that includes a non-circular pinhole like aperture, a first set of slots radially spaced from the aperture, and a region that includes a second set of slots extending to the periphery of the mask and radially spaced from the first set of slots. 
         FIG. 31  is a side view of the mask of  FIG. 30 . 
         FIG. 32  is a frontal plan view of an embodiment of a mask that includes a central pinhole like aperture and a plurality of holes radially spaced from the aperture. 
         FIG. 33  is a side view of the mask of  FIG. 32 . 
         FIG. 34  is an embodiment of a mask that includes two semi-circular mask portions. 
         FIG. 35  is an embodiment of a mask including two half-moon shaped portions. 
         FIG. 36  is an embodiment of a mask that includes a half-moon shaped region and a centrally-located pinhole like aperture. 
         FIG. 37  is an enlarged, diagrammatic view of an embodiment of a mask that includes particulate structure adapted for selectively controlling light transmission through the mask in a low light environment. 
         FIG. 38  is a view of the mask of  FIG. 37  in a bright light environment. 
         FIG. 39  is an embodiment of a mask that includes a barcode formed on the annular region of the mask. 
         FIG. 40  is another embodiment of a mask that includes connectors for securing the mask within the eye. 
         FIG. 41  is a plan view of an embodiment of a mask made of a spiraled fibrous strand. 
         FIG. 42  is a plan view of the mask of  FIG. 41  being removed from the eye. 
         FIG. 43  is a top view of another embodiment of a mask configured to increase depth of focus. 
         FIG. 43A  is an enlarged view of a portion of the view of  FIG. 43 . 
         FIG. 44A  is a cross-sectional view of the mask of  FIG. 43A  taken along the section plane  44 - 44 . 
         FIG. 44B  is a cross-sectional view similar to  FIG. 44A  of another embodiment of a mask. 
         FIG. 44C  is a cross-sectional view similar to  FIG. 44A  of another embodiment of a mask. 
         FIG. 45A  is a graphical representation of one arrangement of holes of a plurality of holes that may be formed on the mask of  FIG. 43 . 
         FIG. 45B  is a graphical representation of another arrangement of holes of a plurality of holes that may be formed on the mask of  FIG. 43 . 
         FIG. 45C  is a graphical representation of another arrangement of holes of a plurality of holes that may be formed on the mask of  FIG. 43 . 
         FIG. 46A  is an enlarged view similar to that of  FIG. 43A  showing a variation of a mask having non-uniform size. 
         FIG. 46B  is an enlarged view similar to that of  FIG. 43A  showing a variation of a mask having a non-uniform facet orientation. 
         FIG. 47  is a top view of another embodiment of a mask having a hole region and a peripheral region. 
         FIG. 48  is a flow chart illustrating one method of aligning a mask with an axis of the eye based on observation of an anatomical feature of the eye. 
         FIG. 49  is a flow chart illustrating one method of screening a patient for the use of a mask. 
         FIGS. 50A-50C  show a mask, similar to those described herein, inserted beneath an epithelium sheet of a cornea. 
         FIGS. 51A-51C  show a mask, similar to those described herein, inserted beneath a Bowman&#39;s membrane of a cornea. 
         FIG. 52  is a front view of an embodiment of a mask with a plurality of generally randomly distributed holes that have substantially equal size as described herein. 
         FIG. 53  is a front view of an embodiment of a mask with larger holes near the center of the annulus as described herein. 
         FIG. 54  is a front view of an embodiment of a mask with a hole region that has three sub-regions as described herein. 
         FIG. 55  is a plot of radial distance from the center of the aperture as a function of percentage of epithelial glucose depletion for the masks of  FIGS. 52 and 53 . 
         FIG. 56  is a graphical representation of one arrangement of holes of a plurality of holes that may be formed in an ophthalmic device. 
         FIG. 57A  illustrates a front plan view of an embodiment of an intraocular lens with a recessed central region on the posterior surface as described herein. 
         FIG. 57B  illustrates a cross-sectional view of the intraocular lens of  FIG. 57A . 
         FIG. 58A  illustrates a front plan view of an embodiment of an intraocular lens with a recessed central region on the anterior surface as described herein. 
         FIG. 58B  illustrates a cross-sectional view of the intraocular lens of  FIG. 58A . 
         FIG. 59A  illustrates a front plan view of an embodiment of an intraocular lens with a recessed central region on the posterior surface and anterior surface as described herein. 
         FIG. 59B  illustrates a cross-sectional view of the intraocular lens of  FIG. 59A . 
         FIG. 60A  illustrates a front plan view of an embodiment of an intraocular lens with two transition zones and two masks as described herein. 
         FIG. 60B  illustrates a cross-sectional view of the intraocular lens of  FIG. 60A . 
         FIG. 61A  illustrates a front plan view of an embodiment of an intraocular lens with two transition zones and a single mask as described herein. 
         FIG. 61B  illustrates a cross-sectional view of the intraocular lens of  FIG. 61A . 
         FIG. 62A  illustrates a front plan view of an embodiment of an intraocular lens with a concave posterior surface and a positive optical power as described herein. 
         FIG. 62B  illustrates a cross-sectional view of the intraocular lens of  FIG. 62A . 
         FIG. 63A  illustrates a front plan view of an embodiment of an intraocular lens with a concave posterior surface and a negative optical power as described herein. 
         FIG. 63B  illustrates a cross-sectional view of the intraocular lens of  FIG. 63A . 
         FIG. 64  is a cross-sectional schematic representation of light passing through the intraocular lens of  FIG. 64B . 
         FIG. 65  is a schematic representation of light from a far object transmitted through an eye having an embodiment of an intraocular lens that is in the capsular bag. 
         FIG. 66A  illustrates a top view of a conventional intraocular lens. 
         FIG. 66B  illustrates a cross-sectional view of the conventional intraocular lens of  FIG. 66A . 
         FIG. 67  shows a transmission spectrum of a 200 micron thick hydrophobic acrylic mask. 
     
    
    
     DETAILED DESCRIPTION 
     This application is directed to ocular devices and implants (e.g., masks) for improving the depth of focus of an eye of a patient and methods and apparatuses for making such ocular devices. The masks generally employ small-aperture vision correction methods to enhance depth of focus in a presbyopic eye thereby providing functional near vision. The masks may be applied to the eye in any manner and in any location, e.g., as an implant in the cornea (sometimes referred to as a “corneal inlay”). The masks can also be embodied in or combined with lenses and applied in other regions of the eye, e.g., as or in combination with contact lenses or intraocular lenses (IOL). 
     The ocular devices and masks described herein can be applied to masks and/or combined with features described in U.S. Patent Publication No. 2006/0265058, filed Apr. 13, 2006, entitled “CORNEAL MASK FORMED OF DEGRADATION RESISTANT POLYMER AND PROVIDING REDUCED CORNEAL DEPOSITS,” U.S. Patent Publication No. 2011/0040376, filed Aug. 13, 2010, entitled “MASKED INTRAOCULAR IMPLANTS AND LENSES,” and International Patent Publication No. WO 2011/020074, filed Aug. 13, 2010, entitled “CORNEAL INLAY WITH NUTRIENT TRANSPORT STRUCTURES,” the entirety of each of which is hereby incorporated by reference. 
     Overview of Depth of Focus Vision Correction 
     Presbyopia is a problem of the human eye that commonly occurs in older human adults wherein the ability to focus becomes limited to inadequate range.  FIGS. 1-6  illustrate how presbyopia interferes with the normal function of the eye and how a mask with a pinhole aperture mitigates the problem. A mask that has a pinhole aperture may be used to improve the depth of focus of a human eye. 
       FIG. 1  shows the human eye, and  FIG. 2  is a side view of the eye  10 . The eye  10  includes a cornea  12  and an intraocular lens  14  posterior to the cornea  12 . The cornea  12  is a first focusing element of the eye  10 . The intraocular lens  14  is a second focusing element of the eye  10 . The eye  10  also includes a retina  16 , which lines the interior of the rear surface of the eye  10 . The retina  16  includes the receptor cells which are primarily responsible for the sense of vision. The retina  16  includes a highly sensitive region, known as the macula, where signals are received and transmitted to the visual centers of the brain via the optic nerve  18 . The retina  16  also includes a point with particularly high sensitivity  20 , known as the fovea. As discussed in more detail in connection with  FIG. 8 , the fovea  20  is slightly offset from the axis of symmetry of the eye  10 . 
     The eye  10  also includes a ring of pigmented tissue known as the iris  22 . The iris  22  includes smooth muscle for controlling and regulating the size of an opening  24  in the iris  22 , which is known as the pupil. An entrance pupil  26  is seen as the image of the iris  22  viewed through the cornea  12  (See  FIG. 4 ). 
     The eye  10  resides in an eye-socket in the skull and is able to rotate therein about a center of rotation  30 . 
       FIG. 3  shows the transmission of light through the eye  10  of a presbyopic patient. Due to either an aberration in the cornea  12  or the intraocular lens  14 , or loss of muscle control, light rays  32  entering the eye  10  and passing through the cornea  12  and the intraocular lens  14  are refracted in such a way that the light rays  32  do not converge at a single focal point on the retina  16 .  FIG. 3  illustrates that in a presbyopic patient, the light rays  32  often converge at a point behind the retina  16 . As a result, the patient experiences blurred vision. 
     Turning now to  FIG. 4 , there is shown the light transmission through the eye  10  to which a mask  34  has been applied. The mask  34  is shown implanted in the cornea  12  in  FIG. 4 . However, as discussed below, it will be understood that the mask  34  can be, in various modes of application, implanted in the cornea  12  (as shown), used as a contact lens placed over the cornea  12 , incorporated in the intraocular lens  14  (including the patient&#39;s original lens or an implanted lens), or otherwise positioned on or in the eye  10 . In the illustrated embodiment, the light rays  32  that pass through the mask  34 , the cornea  12 , and the lens  14  converge at a single focal point on the retina  16 . The light rays  32  that would not converge at the single point on retina  16  are blocked by the mask  34 . As discussed below, it is desirable to position the mask  34  on the eye  10  so that the light rays  32  that pass through the mask  34  converge at the fovea  20 . 
     Turning now to  FIG. 6 , there is shown one embodiment of the mask  34 . A variety of variations of the mask  34  are discussed hereinbelow. As seen, the mask  34  preferably includes an annular region  36  surrounding a pinhole opening or aperture  38  substantially centrally located on the mask  34 . The pinhole aperture  38  is generally located around a central axis  39 , referred to herein as the optical axis of the mask  34 . The pinhole aperture  38  preferably is in the shape of a circle. It has been reported that a circular aperture, such as the aperture  38  may, in some patients, produce a so-called “halo effect” where the patient perceives a shimmering image around the object being viewed. Accordingly, it may be desirable to provide an aperture  38  in a shape that diminishes, reduces, or completely eliminates the so-called “halo effect.” 
     Ophthalmic Devices Employing Depth of Focus Correction 
       FIGS. 7-42  illustrate a variety of embodiments of masks that can improve the vision of a patient with presbyopia. The masks described in connection with  FIGS. 7-42  are similar to the mask  34 , except as described differently below. Any of the masks discussed below, e.g., those shown in  FIGS. 7-42 , can be made of any of the materials discussed herein. The mask  34  and any of the masks discussed below can include a locator structure, such as is discussed in U.S. Patent Publication No. 2006/0235428, filed Apr. 14, 2005 with the title “OCULAR INLAY WITH LOCATOR,” which is incorporated herein by reference in its entirety. The masks described in connection with  FIGS. 7-42  can be used and applied to the eye  10  of a patient in a similar fashion to the mask  34 . For example,  FIG. 7  shows an embodiment of a mask  34   a  that includes an aperture  38   a  formed in the shape of a hexagon.  FIG. 8  shows another embodiment of a mask  34   b  that includes an aperture  38   b  formed in the shape of an octagon.  FIG. 9  shows another embodiment of a mask  34   c  that includes an aperture  38   c  formed in the shape of an oval, while  FIG. 10  shows another embodiment of a mask  34   d  that includes an aperture  38   d  formed in the shape of a pointed oval.  FIG. 11  shows another embodiment of a mask  34   e  wherein the aperture  38   e  is formed in the shape of a star or starburst. 
       FIGS. 12-14  illustrate further embodiments that have tear-drop shaped apertures.  FIG. 12  shows a mask  34   f  that has a tear-drop shaped aperture  38   f  that is located above the true center of the mask  34   f .  FIG. 13  shows a mask  34   g  that has a tear-drop shaped aperture  38   g  that is substantially centered in the mask  34   g .  FIG. 14  shows a mask  34   h  that has a tear-drop shaped aperture  38   h  that is below the true center of the mask  34   h .  FIGS. 12-14  illustrate that the position of aperture can be tailored, e.g., centered or off-center, to provide different effects. For example, an aperture that is located below the true center of a mask generally will allow more light to enter the eye because the upper portion of the aperture  34  will not be covered by the eyelid of the patient. Conversely, where the aperture is located above the true center of the mask, the aperture may be partially covered by the eyelid. Thus, the above-center aperture may permit less light to enter the eye. 
       FIG. 15  shows an embodiment of a mask  34   i  that includes an aperture  38   i  formed in the shape of a square.  FIG. 16  shows an embodiment of a mask  34   j  that has a kidney-shaped aperture  38   j . It will be appreciated that the apertures shown in  FIGS. 7-16  are merely exemplary of non-circular apertures. Other shapes and arrangements may also be provided and are within the scope of the present invention. 
     The mask  34  preferably has a constant thickness, as discussed below. However, in some embodiments, the thickness of the mask may vary between the inner periphery (near the aperture  38 ) and the outer periphery.  FIG. 17  shows a mask  34   k  that has a convex profile, i.e., that has a gradually decreasing thickness from the inner periphery to the outer periphery.  FIG. 18  shows a mask  34   l  that has a concave profile, i.e., that has a gradually increasing thickness from the inner periphery to the outer periphery. Other cross-sectional profiles are also possible. 
     The annular region  36  is at least partially and preferably completely opaque. The opacity of the annular region  36  prevents light from being transmitted through the mask  34  (as generally shown in  FIG. 5 ). Opacity of the annular region  36  may be achieved in any of several different ways. 
     For example, in one embodiment, the material used to make mask  34  may be naturally opaque. Alternatively, the material used to make the mask  34  may be substantially clear, but treated with a dye or other pigmentation agent to render region  36  substantially or completely opaque. In still another example, the surface of the mask  34  may be treated physically or chemically (such as by etching) to alter the refractive and transmissive properties of the mask  34  and make it less transmissive to light. 
     In still another alternative, the surface of the mask  34  may be treated with a particulate deposited thereon. For example, the surface of the mask  34  may be deposited with particulate of titanium, gold or carbon to provide opacity to the surface of the mask  34 . In another alternative, the particulate may be encapsulated within the interior of the mask  34 , as generally shown in  FIG. 19 . Finally, the mask  34  may be patterned to provide areas of varying light transmissivity, as generally shown in  FIGS. 24-33 , which are discussed in detail below. 
     Modifying Light Transmission Through Ophthalmic Devices 
     Turning to  FIG. 20 , there is shown a mask  34   m  formed or made of a woven fabric, such as a mesh of polyester fibers. The mesh may be a cross-hatched mesh of fibers. The mask  34   m  includes an annular region  36   m  surrounding an aperture  38   m . The annular region  36   m  comprises a plurality of generally regularly positioned apertures  36   m  in the woven fabric allow some light to pass through the mask  34   m . The amount of light transmitted can be varied and controlled by, for example, moving the fibers closer together or farther apart, as desired. Fibers more densely distributed allow less light to pass through the annular region  36   m . Alternatively, the thickness of fibers can be varied to allow more or less light through the openings of the mesh. Making the fiber strands larger results in the openings being smaller. 
       FIG. 22  shows an embodiment of a mask  34   n  that includes an annular region  36   n  that has sub-regions with different opacities. The opacity of the annular region  36   n  may gradually and progressively increase or decrease, as desired.  FIG. 22  shows one embodiment where a first area  42  closest to an aperture  38   n  has an opacity of approximately 43%. In this embodiment, a second area  44 , which is outlying with respect to the first area  42 , has a greater opacity, such as 70%. In this embodiment, a third area  46 , which is outlying with respect to the second area  42 , has an opacity of between 85 to 100%. The graduated opacity of the type described above and shown in  FIG. 22  is achieved in one embodiment by, for example, providing different degrees of pigmentation to the areas  42 ,  44  and  46  of the mask  34   n . In another embodiment, light blocking materials of the type described above in variable degrees may be selectively deposited on the surface of a mask to achieve a graduated opacity. 
     In another embodiment, the mask may be formed from co-extruded rods made of material having different light transmissive properties. The co-extruded rod may then be sliced to provide disks for a plurality of masks, such as those described herein. 
       FIGS. 24-33  shows examples of masks that have been modified to provide regions of differing opacity. For example,  FIG. 24  shows a mask  34   o  that includes an aperture  38   o  and a plurality of cutouts  48  in the pattern of radial spokes extending from near the aperture  38   o  to an outer periphery  50  of the mask  34   o .  FIG. 24  shows that the cutouts  48  are much more densely distributed about a circumference of the mask near aperture  38   o  than are the cutouts  48  about a circumference of the mask near the outer periphery  50 . Accordingly, more light passes through the mask  34   o  nearer aperture  38   o  than near the periphery  50 . The change in light transmission through the mask  34   o  is gradual. 
       FIGS. 26-27  show another embodiment of a mask  34   p . The mask  34   p  includes an aperture  38   p  and a plurality of circular cutouts  49   p , and a plurality of cutouts  51   p . The circular cutouts  49   p  are located proximate the aperture  38   p . The cutouts  51   p  are located between the circular cutouts  49   p  and the periphery  50   p . The density of the circular cutouts  49   p  generally decreases from the near the aperture  38   p  toward the periphery  50   p . The periphery  50   p  of the mask  34   p  is scalloped by the presence of the cutouts  54   p , which extend inward from the periphery  50   p , to allow some light to pass through the mask at the periphery  50   p.    
       FIGS. 28-29  shows another embodiment similar to that of  FIGS. 26-27  wherein a mask  34   q  includes a plurality of circular cutouts  49   q  and a plurality of cutouts  51   q . The cutouts  51   q  are disposed along the outside periphery  50   q  of the mask  34   q , but not so as to provide a scalloped periphery. 
       FIGS. 30 and 31  illustrate an embodiment of a mask  34   r  that includes an annular region  36   r  that is patterned and an aperture  38   r  that is non-circular. As shown in  FIG. 30 , the aperture  38   r  is in the shape of a starburst. Surrounding the aperture  38   r  is a series of cutouts  51   r  that are more densely spaced toward the aperture  38   r . The mask  34   r  includes an outer periphery  50   r  that is scalloped to provide additional light transmission at the outer periphery  50   r.    
       FIGS. 32 and 33  show another embodiment of a mask  34   s  that includes an annular region  36   s  and an aperture  38   s . The annular region  36   s  is located between an outer periphery  50   s  of the mask  34   s  and the aperture  38   s . The annular region  36   s  is patterned. In particular, a plurality of circular openings  56   s  is distributed over the annular region  36   s  of the mask  34   s . It will be appreciated that the density of the openings  56   s  is greater near the aperture  38   s  than near the periphery  50   s  of the mask  34   s . As with the examples described above, this results in a gradual increase in the opacity of the mask  34   s  from aperture  38   s  to periphery  50   s.    
       FIGS. 34-36  show further embodiments. In particular,  FIG. 34  shows a mask  34   t  that includes a first mask portion  58   t  and a second mask portion  60   t . The mask portions  58   t ,  60   t  are generally “C-shaped.” As shown in  FIG. 34 , the mask portions  58   t ,  60   t  are implanted or inserted such that the mask portions  58   t ,  60   t  define a pinhole or aperture  38   t.    
       FIG. 35  shows another embodiment wherein a mask  34   u  includes two mask portions  58   u ,  43   u . Each mask portion  58   u ,  43   u  is in the shape of a half-moon and is configured to be implanted or inserted in such a way that the two halves define a central gap or opening  45   u , which permits light to pass therethrough. Although opening  45   u  is not a circular pinhole, the mask portions  58   u ,  43   u  in combination with the eyelid (shown as dashed line  64 ) of the patient provide a comparable pinhole effect. 
       FIG. 36  shows another embodiment of a mask  34   v  that includes an aperture  38   v  and that is in the shape of a half-moon. As discussed in more detail below, the mask  34   v  may be implanted or inserted into a lower portion of the cornea  12  where, as described above, the combination of the mask  34   v  and the eyelid  64  provides the pinhole effect. 
     Other embodiments employ different ways of controlling the light transmissivity through a mask. For example, the mask may be a gel-filled disk, as shown in  FIG. 19 . The gel may be a hydrogel or collagen, or other suitable material that is biocompatible and compatible with the mask material and can be introduced into the interior of the mask. The gel within the mask may include particulate  53  suspended within the gel. Examples of suitable particulate are gold, titanium, and carbon particulate, which, as discussed above, may alternatively be deposited on the surface of the mask. 
     The material of the mask  34  may be any biocompatible polymeric material. Where a gel is used, the material is suitable for holding a gel. Examples of suitable materials for the mask  34  include the preferred polymethylmethacrylate or other suitable polymers, such as polycarbonates and the like. Of course, as indicated above, for non-gel-filled materials, a preferred material may be a fibrous material, such as a Dacron mesh. Of the materials for use in the mask are those described in section VI herein. 
     The mask  34  may also be made to include a medicinal fluid or material, such as an antibiotic or other wound healing modulator that can be selectively released after application, insertion, or implantation of the mask  34  into the eye of the patient. Release of an antibiotic or other wound healing modulator after application, insertion, or implantation provides faster and/or improved healing of the incision. The mask  34  may also be coated with other desired drugs or antibiotics. For example, it is known that cholesterol deposits can build up on the eye. Accordingly, the mask  34  may be provided with a releasable cholesterol deterring drug. The drug may be coated on the surface of the mask  34  or, in an alternative embodiment, incorporated into the polymeric material (such as PMMA) from which the mask  34  is formed. 
       FIGS. 37 and 38  illustrate one embodiment where a mask  34   w  comprises a plurality of nanites  68 . “Nanites” are small particulate structures that have been adapted to selectively transmit or block light entering the eye of the patient. The particles may be of a very small size typical of the particles used in nanotechnology applications. The nanites  68  are suspended in the gel or otherwise inserted into the interior of the mask  34   w , as generally shown in  FIGS. 37 and 38 . The nanites  68  can be preprogrammed to respond to different light environments. 
     Thus, as shown in  FIG. 38 , in a high light environment, the nanites  68  turn and position themselves to substantially and selectively block some of the light from entering the eye. However, in a low light environment where it is desirable for more light to enter the eye, nanites may respond by turning or be otherwise positioned to allow more light to enter the eye, as shown in  FIG. 97 . 
     Nano-devices or nanites are crystalline structures grown in laboratories. The nanites may be treated such that they are receptive to different stimuli such as light. In accordance with one aspect of the present invention, the nanites can be imparted with energy where, in response to a low light and high light environments, they rotate in the manner described above and generally shown in  FIG. 38 . 
     Nanoscale devices and systems and their fabrication are described in Smith et al., “Nanofabrication,” Physics Today, February 1990, pp. 24-30 and in Craighead, “Nanoelectromechanical Systems,” Science, Nov. 24, 2000, Vol. 290, pp. 1502-1505, both of which are incorporated by reference herein in their entirety. Tailoring the properties of small-sized particles for optical applications is disclosed in Chen et al. “Diffractive Phase Elements Based on Two-Dimensional Artificial Dielectrics,” Optics Letters, Jan. 15, 1995, Vol. 20, No. 2, pp. 121-123, also incorporated by reference herein in its entirety. 
     Masks  34  made in accordance with the present invention may be further modified to include other properties.  FIG. 39  shows one embodiment of a mask  34   x  that includes a bar code  66  or other printed indicia. 
     Methods of Inserting or Removing an Ophthalmic Device 
     The masks described herein may be incorporated into the eye of a patient in different ways. For example, as discussed in more detail below in connection with FIG.  49 , the mask  34  may be provided as a contact lens placed on the surface of the eyeball  10 . Alternatively, the mask  34  may be incorporated in an artificial intraocular lens designed to replace the original lens  14  of the patient. The mask  34  may be provided as a corneal implant or inlay, where it is physically inserted between the layers of the cornea  12 . 
     When used as a corneal implant, layers of the cornea  12  are peeled away to allow insertion of the mask  34 . Typically, the optical surgeon (typically using a laser) cuts away and peels away a flap of the overlying corneal epithelium. The mask  34  is then inserted and the flap is placed back in its original position where, over time, it grows back and seals the eyeball. In some embodiments, the mask  34  is attached or fixed to the eye  10  by support strands  60  and  62  shown in  FIG. 40  and generally described in U.S. Pat. No. 4,976,732, incorporated by reference herein in its entirety. 
     In certain circumstances, to accommodate the mask  34 , the surgeon may be required to remove additional corneal tissue. Thus, in one embodiment, the surgeon may use a laser to peel away additional layers of the cornea  12  to provide a pocket that will accommodate the mask  34 . Application of the mask  34  to the cornea  12  of the eye  10  of a patient is described in greater detail in connection with  FIGS. 50A-51C . 
     Removal of the mask  34  may be achieved by simply making an additional incision in the cornea  12 , lifting the flap and removing the mask  34 . Alternatively, ablation techniques may be used to completely remove the mask  34 . 
       FIGS. 41 and 42  illustrate another embodiment, of a mask  34   y  that includes a coiled strand  80  of a fibrous or other material. Strand  80  is coiled over itself to form the mask  34   y , which may therefore be described as a spiral-like mask. This arrangement provides a pinhole or aperture  38   y  substantially in the center of the mask  34   y . The mask  34   y  can be removed by a technician or surgeon who grasps the strand  80  with tweezers  82  through an opening made in a flap of the corneal  12 .  FIG. 42  shows this removal technique. 
     Further mask details are disclosed in U.S. Pat. No. 4,976,732, issued Dec. 11, 1990 and in U.S. patent application Ser. No. 10/854,033, filed May 26, 2004, both of which are incorporated by reference herein in their entirety. 
     Additives to Reduce Corneal Deposits and/or Promote Proper Healing 
     In some circumstances, corneal implants are associated with deposits on the cornea. Loading of one or more polyanionic compounds into the polymeric material of a corneal implant may reduce and/or substantially eliminate deposits on the cornea, possibly by attracting and/or retaining growth factors. 
     In a preferred embodiment the one or more polyanionic compounds include carbohydrates, proteins, natural proteoglycans, and/or the glycosaminoglycan moieties of proteoglycans, as well as derivatives (such as sulfated derivatives) and salts of compounds such as those in the aforementioned categories. Preferred polyanionic compounds include one or more of dermatan sulfate, chondroitin sulfate, keratan sulfate, heparan sulfate, heparin, dextran sulfate, hyaluronic acid, pentosan polysulfate, xanthan, carrageenan, fibronectin, laminin, chondronectin, vitronectin, poly L-lysine salts, and anionic, preferably sulfated, carbohydrates such as alginate may also be used, as well as salts and derivatives of the listed compounds. Examples of preferred anionic compounds and combinations of polyanionic compounds include keratan sulfate/chondroitin sulfate-proteoglycan, dermatan sulfate proteoglycan, and dextran sulfate. 
     In one embodiment, a polyanionic compound comprises acidic sulfate moieties and the sulfur content is greater than about 5% by weight, preferably greater than about 10% by weight. In an even more preferred embodiment, the average molecular weight of a polyanionic compound is about 40,000 to 500,000 Daltons. 
     In a preferred embodiment, the total weight of the one or more polyanionic compounds in the loaded polymeric material is about 0.1% by weight to about 50% by weight, including about 5% by weight to about 20% by weight, about 12% by weight to about 17% by weight, about 0.5% by weight to about 4% by weight, and about 5% by weight to about 15% by weight. It should be noted that the percentages recited herein in relation to polyanionic compounds, opacification agents and wound healing modulator compounds are percent by weight with 100% being the total weight of the entire mask composition including all additives. 
     In one embodiment, the body of the mask is formed from a polymeric material having one or more polyanionic compounds loaded therein. Loading of a polyanionic compound is performed by mixing the polyanionic compound with the resin and any other additives of the polymeric material prior to molding or casting of the body of the mask. Although some of a polyanionic compound that is loaded into the polymeric material may be on the surface of the mask, loading is to be distinguished from coating in that a coated material would not have polyanionic material throughout the bulk of the mask. 
     The loaded polymeric material is preferably made by suspending or dissolving polymer, one or more polyanionic compounds and any other additives (such as wound healing modulators, as described below) in a solvent or solvent system, and then casting a film whereby the solvent or solvent system is removed such as by evaporation. Preferred casting methods include spin casting and other methods, including those known in the art, which can form a thin material of relatively even thickness. Although other methods of making thin substrates, such as extrusion, may be used, solvent casting is generally preferred because it does not need to be done at high temperatures that may cause degradation of some polyanionic compounds. The polymer, polyanionic compound, and/or other additives may be ground or milled, such as by ball milling, to reduce the particle size of the material prior to suspending, dissolving or melting as part of making the mask. 
     In methods using solvent casting, preferred solvents include those which are capable of dissolving the polymeric material, polyanionic compounds, and/or other additives. A suitable solvent or solvent system (i.e. combination of two or more solvents) may be chosen by one skilled in the art based upon known solubilities for a given polymeric material and/or routine experimentation based upon chemical principles. In solvent casting methods, the temperature of the solvent or solution should be no higher than the boiling point of the solvent or solvent system, and is preferably about 10° C. to about 70° C. During or after casting of the solution to form a film, the temperature may be elevated, including above the boiling point. 
     In one embodiment, a mask, such as an inlay, comprising PVDF, dextran sulfate, and carbon was made by spin casting. 100 grams of PVDC (about 71% by weight) in the form of pellets was dissolved in 400 grams of dimethylacetamide. 17 grams of carbon (about 12% by weight) and 24 grams of dextran sulfate (about 17% by weight) are ball milled to reduce particle size and then added to the PVDF/DMA solution. The percentages by weight are the percentages of the solids portion, that is the portion that is not the solvent. The solution was at room temperature (approximately 17° C. to about 25° C.). The solution was then spin cast to form a film. 
     In one embodiment, the device includes a wound healing modulator. When present, the wound healing modulator is on at least one surface or it may be loaded into the polymeric material. A wound healing modulator is defined as a compound that assists in proper healing of a wound, such as by increasing the rate of healing, decreasing inflammation, moderating or suppressing immune response, decreasing scarring, decreasing cell proliferation, reducing infection, encouraging transdifferentiation of keratocytes into cells that lay down collagen, and the like. Wound healing modulators include, without limitation, antibiotics, antineoplastics including antimitotics, antimetabolics and antibiotic types, anti-inflammatories, immunosuppressants, and antifungals. Preferred compounds include, but are not limited to, fluorouracil, mitomycin C, paclitaxel, NSAIDs (e.g. ibuprofen, naproxen, flurbiprofen, carprofen, suprofen, ketoprofen), and cyclosporins. Other preferred compounds include proteoglycans, glycosaminoglycans, and salts and derivatives thereof, as well as other carbohydrates and/or proteins, including those disclosed above. 
     A wound healing modulator may be included in the mask by loading it into the polymeric material as discussed above with respect to the polyanionic compounds. It may also be included by binding it to one or more surfaces of the device. The “binding” of the wound healing modulator to the device may occur by phenomena that do not generally involve chemical bonds, including adsorption, hydrogen bonding, van der Waals forces, electrostatic attraction, ionic bonding, and the like, or it may occur by phenomena that do include chemical bonds. In a preferred embodiment, the total weight of the one or more wound healing modulator compounds in the loaded polymeric material is about 0.1% by weight to about 50% by weight, including about 5% by weight to about 20% by weight, about 12% by weight to about 17% by weight, about 0.5% by weight to about 4% by weight, and about 5% by weight to about 15% by weight. 
     In one embodiment, carbon, gold or other material on a surface of the mask acts as an adsorbent or otherwise participates in the binding of one or more wound healing modulators to the implant. The material on the surface of the mask that participates in binding the wound healing modulator may be part of the bulk material of the implant (distributed throughout the implant or which migrates to the surface during and/or following formation of the implant) and/or deposited on a surface of the mask, such as an opacification agent as described elsewhere infra. The implant is then exposed to one or more wound healing modulators, such as by dipping in a solution (including dispersions and emulsions) comprising at least one wound healing modulator, to allow wound healing modulator(s) to bind to the implant. The solvent used to assist in applying and binding the wound healing modulator to the implant is preferably biocompatible, does not leave a harmful residue, and/or does not cause dissolution or swelling of the polymeric material of the mask. If more than one wound healing modulator is used, binding may be performed by dipping in a single solution containing all desired wound healing modulators or by dipping the implant in two or more successive solutions, each of which contains one or more of the desired wound healing modulators. The process of binding wound healing modulator to the implant may be done at any time. In one embodiment, at least some of the wound healing modulator is bound to the implant as part of the manufacturing process. In another embodiment, a medical practitioner, such as an ophthalmologist, binds at least some of the wound healing modulator to the implant just prior to implantation. 
     In alternate embodiments, one or more wound healing modulators are bound to the implant using any suitable method for binding drugs or other useful compounds to implants and medical devices and/or using methods for making drug delivery devices which deliver a drug locally in the area of implantation or placement over a period of time. 
     Ophthalmic Devices Providing Nutrient Transport 
     Many of the foregoing masks can be used to improve the depth of focus of a patient. Various additional mask embodiments are discussed below. Some of the embodiments described below include nutrient transport structures that are configured to enhance or maintain nutrient flow between adjacent tissues by facilitating transport of nutrients across the mask. The nutrient transport structures of some of the embodiments described below are configured to at least substantially prevent nutrient depletion in adjacent tissues. The nutrient transport structures can decrease negative effects due to the presence of the mask in adjacent corneal layers when the mask is implanted in the cornea, increasing the longevity of the masks. The inventors have discovered that certain arrangements of nutrient transport structures generate diffraction patterns that interfere with the vision improving effect of the masks described herein. Accordingly, certain masks are described herein that include nutrient transport structures that do not generate diffraction patterns or otherwise interfere with the vision enhancing effects of the mask embodiments. 
       FIGS. 43-44  show one embodiment of a mask  100  configured to increase depth of focus of an eye of a patient suffering from presbyopia. The mask  100  is similar to the masks hereinbefore described, except as described differently below. Also, the mask  100  can be formed by any suitable process, such as those discussed below with variations of such processes. The mask  100  is configured to be applied to an eye of a patient, e.g., by being implanted in the cornea of the patient. The mask  100  may be implanted within the cornea in any suitable manner, such as those discussed above in connection with  FIGS. 50A-51C . 
     In one embodiment, the mask  100  includes a body  104  that has an anterior surface  108  and a posterior surface  112 . In one embodiment, the body  104  is capable of substantially maintaining natural nutrient flow between the first corneal layer and the second corneal layer. In one embodiment, the material is selected to maintain at least about ninety-six percent of the natural flow of at least one nutrient (e.g., glucose) between a first corneal layer (e.g., the layer  1210 ) and a second corneal layer (e.g., the layer  1220 ). The body  104  may be formed of any suitable material, including at least one of an open cell foam material, an expanded solid material, and a substantially opaque material. In one embodiment, the material used to form the body  104  has relatively high water content. 
     In one embodiment, the mask  100  includes and a nutrient transport structure  116 . The nutrient transport structure  116  may comprise a plurality of holes  120 . The holes  120  are shown on only a portion of the mask  100 , but the holes  120  preferably are located throughout the body  104  in one embodiment. In one embodiment, the holes  120  are arranged in a hex pattern, which is illustrated by a plurality of locations  120 ′ in  FIG. 45A . As discussed below, a plurality of locations may be defined and later used in the later formation of a plurality of holes  120  on the mask  100 . The mask  100  has an outer periphery  124  that defines an outer edge of the body  104 . In some embodiments, the mask  100  includes an aperture  128  at least partially surrounded by the outer periphery  124  and a non-transmissive portion  132  located between the outer periphery  124  and the aperture  128 . 
     Preferably the mask  100  is symmetrical, e.g., symmetrical about a mask axis  136 . In one embodiment, the outer periphery  124  of the mask  100  is circular. The masks in general have has a diameter within the range of from about 3 mm to about 8 mm, often within the range of from about 3.5 mm to about 6 mm, and less than about 6 mm in one embodiment. In another embodiment, the mask is circular and has a diameter in the range of 4 to 6 mm. In another embodiment, the mask  100  is circular and has a diameter of less than 4 mm. The outer periphery  124  has a diameter of about 3.8 mm in another embodiment. In some embodiments, masks that are asymmetrical or that are not symmetrical about a mask axis provide benefits, such as enabling a mask to be located or maintained in a selected position with respect to the anatomy of the eye. 
     The body  104  of the mask  100  may be configured to coupled with a particular anatomical region of the eye. The body  104  of the mask  100  may be configured to conform to the native anatomy of the region of the eye in which it is to be applied. For example, where the mask  100  is to be coupled with an ocular structure that has curvature, the body  104  may be provided with an amount of curvature along the mask axis  136  that corresponds to the anatomical curvature. For example, one environment in which the mask  100  may be deployed is within the cornea of the eye of a patient. The cornea has an amount of curvature that varies from person to person about a substantially constant mean value within an identifiable group, e.g., adults. When applying the mask  100  within the cornea, at least one of the anterior and posterior surfaces  108 ,  112  of the mask  100  may be provided with an amount of curvature corresponding to that of the layers of the cornea between which the mask  100  is applied. 
     In some embodiments, the mask  100  has a desired amount of optical power. Optical power may be provided by configuring the at least one of the anterior and posterior surfaces  108 ,  112  with curvature. In one embodiment, the anterior and posterior surfaces  108 ,  112  are provided with different amounts of curvature. In this embodiment, the mask  100  has varying thickness from the outer periphery  124  to the aperture  128 . 
     In one embodiment, one of the anterior surface  108  and the posterior surface  112  of the body  104  is substantially planar. In one planar embodiment, very little or no uniform curvature can be measured across the planar surface. In another embodiment, both of the anterior and posterior surfaces  108 ,  112  are substantially planar. In general, the thickness of the inlay may be within the range of from about 1 micron to about 40 micron, and often in the range of from about 5 micron to about 20 micron. In one embodiment, the body  104  of the mask  100  has a thickness  138  of between about 5 micron and about 10 micron. In one embodiment, the thickness  138  of the mask  100  is about 5 micron. In another embodiment, the thickness  138  of the mask  100  is about 8 micron. In another embodiment, the thickness  138  of the mask  100  is about 10 micron. 
     Thinner masks generally are more suitable for applications wherein the mask  100  is implanted at a relatively shallow location in (e.g., close to the anterior surface of) the cornea. In thinner masks, the body  104  may be sufficiently flexible such that it can take on the curvature of the structures with which it is coupled without negatively affecting the optical performance of the mask  100 . In one application, the mask  100  is configured to be implanted about 5 um beneath the anterior surface of the cornea. In another application, the mask  100  is configured to be implanted about 52 um beneath the anterior surface of the cornea. In another application, the mask  100  is configured to be implanted about 125 um beneath the anterior surface of the cornea. Further details regarding implanting the mask  100  in the cornea are discussed above in connection with  FIGS. 50A-51C . 
     A substantially planar mask has several advantages over a non-planar mask. For example, a substantially planar mask can be fabricated more easily than one that has to be formed to a particular curvature. In particular, the process steps involved in inducing curvature in the mask  100  can be eliminated. Also, a substantially planar mask may be more amenable to use on a wider distribution of the patient population (or among different sub-groups of a broader patient population) because the substantially planar mask uses the curvature of each patient&#39;s cornea to induce the appropriate amount of curvature in the body  104 . 
     In some embodiments, the mask  100  is configured specifically for the manner and location of coupling with the eye. In particular, the mask  100  may be larger if applied over the eye as a contact lens or may be smaller if applied within the eye posterior of the cornea, e.g., proximate a surface of the lens of the eye. As discussed above, the thickness  138  of the body  104  of the mask  100  may be varied based on where the mask  100  is implanted. For implantation at deeper levels within the cornea, a thicker mask may be advantageous. Thicker masks are advantageous in some applications. For example, they are generally easier to handle, and therefore are easier to fabricate and to implant. Thicker masks may benefit more from having a preformed curvature than thinner masks. A thicker mask could be configured to have little or no curvature prior to implantation if it is configured to conform to the curvature of the native anatomy when applied. 
     The aperture  128  is configured to transmit substantially all incident light along the mask axis  136 . The non-transmissive portion  132  surrounds at least a portion of the aperture  128  and substantially prevents transmission of incident light thereon. As discussed in connection with the above masks, the aperture  128  may be a through-hole in the body  104  or a substantially light transmissive (e.g., transparent) portion thereof. The aperture  128  of the mask  100  generally is defined within the outer periphery  124  of the mask  100 . The aperture  128  may take any of suitable configurations, such as those described above in connection with  FIGS. 6-42 . 
     In one embodiment, the aperture  128  is substantially circular and is substantially centered in the mask  100 . The size of the aperture  128  may be any size that is effective to increase the depth of focus of an eye of a patient suffering from presbyopia. For example, the aperture  128  can be circular, having a diameter of less than about 2.2 mm in one embodiment. In another embodiment, the diameter of the aperture is between about 1.8 mm and about 2.2 mm. In another embodiment, the aperture  128  is circular and has a diameter of about 1.8 mm or less. In another embodiment, the diameter of the aperture is about 1.6 mm. Most apertures will have a diameter within the range of from about 1.0 mm to about 2.5 mm, and often within the range of from about 1.3 mm to about 1.9 mm. 
     The non-transmissive portion  132  is configured to prevent transmission of radiant energy through the mask  100 . For example, in one embodiment, the non-transmissive portion  132  prevents transmission of substantially all of at least a portion of the spectrum of the incident radiant energy. In one embodiment, the non-transmissive portion  132  is configured to prevent transmission of substantially all visible light, e.g., radiant energy in the electromagnetic spectrum that is visible to the human eye. The non-transmissive portion  132  may substantially prevent transmission of radiant energy outside the range visible to humans in some embodiments. 
     As discussed above in connection with  FIG. 3 , preventing transmission of light through the non-transmissive portion  132  decreases the amount of light that reaches the retina and the fovea that would not converge at the retina and fovea to form a sharp image. As discussed above in connection with  FIG. 4 , the size of the aperture  128  is such that the light transmitted therethrough generally converges at the retina or fovea. Accordingly, a much sharper image is presented to the eye than would otherwise be the case without the mask  100 . 
     In one embodiment, the non-transmissive portion  132  prevents transmission of about 90 percent of incident light. In another embodiment, the non-transmissive portion  132  prevents transmission of about 92 percent of all incident light. The non-transmissive portion  132  of the mask  100  may be configured to be opaque to prevent the transmission of light. As used herein the term “opaque” is intended to be a broad term meaning capable of preventing the transmission of radiant energy, e.g., light energy, and also covers structures and arrangements that absorb or otherwise block all or less than all or at least a substantial portion of the light. In one embodiment, at least a portion of the body  104  is configured to be opaque to more than 99 percent of the light incident thereon. 
     As discussed above, the non-transmissive portion  132  may be configured to prevent transmission of light without absorbing the incident light. For example, the mask  100  could be made reflective or could be made to interact with the light in a more complex manner, as discussed in U.S. Pat. No. 6,551,424, issued Apr. 29, 2003, which is hereby incorporated by reference herein in its entirety. 
     As discussed above, the mask  100  also has a nutrient transport structure that in some embodiments comprises the plurality of holes  120 . The presence of the plurality of holes  120  (or other transport structure) may affect the transmission of light through the non-transmissive portion  132  by potentially allowing more light to pass through the mask  100 . In one embodiment, the non-transmissive portion  132  is configured to absorb about 99 percent or more of the incident light from passing through the mask  100  without holes  120  being present. The presence of the plurality of holes  120  allows more light to pass through the non-transmissive portion  132  such that only about 92 percent of the light incident on the non-transmissive portion  132  is prevented from passing through the non-transmissive portion  132 . The holes  120  may reduce the benefit of the aperture  128  on the depth of focus of the eye by allowing more light to pass through the non-transmissive portion to the retina. 
     Reduction in the depth of focus benefit of the aperture  128  due to the holes  120  is balanced by the nutrient transmission benefits of the holes  120 . In one embodiment, the transport structure  116  (e.g., the holes  120 ) is capable of substantially maintaining natural nutrient flow from a first corneal layer (i.e., one that is adjacent to the anterior surface  108  of the mask  100 ) to the second corneal layer (i.e., one that is adjacent to the posterior surface  112  of the mask  100 ). The plurality of holes  120  are configured to enable nutrients to pass through the mask  100  between the anterior surface  108  and the posterior surface  112 . As discussed above, the holes  120  of the mask  100  shown in  FIG. 43  may be located anywhere on the mask  100 . Other mask embodiments described herein below locate substantially all of the nutrient transport structure in one or more regions of a mask. 
     The holes  120  of  FIG. 43  extends at least partially between the anterior surface  108  and the posterior surface  112  of the mask  100 . In one embodiment, each of the holes  120  includes a hole entrance  140  and a hole exit  164 . The hole entrance  140  is located adjacent to the anterior surface  108  of the mask  100 . The hole exit  164  is located adjacent to the posterior surface  112  of the mask  100 . In one embodiment, each of the holes  120  extends the entire distance between the anterior surface  108  and the posterior surface  112  of the mask  100 . 
     The transport structure  116  is configured to maintain the transport of one or more nutrients across the mask  100 . The transport structure  116  of the mask  100  provides sufficient flow of one or more nutrients across the mask  100  to prevent depletion of nutrients at least at one of the first and second corneal layers (e.g., the layers  1210  and  1220 ). One nutrient of particular importance to the viability of the adjacent corneal layers is glucose. The transport structure  116  of the mask  100  provides sufficient flow of glucose across the mask  100  between the first and second corneal layers to prevent glucose depletion that would harm the adjacent corneal tissue. Thus, the mask  100  is capable of substantially maintaining nutrient flow (e.g., glucose flow) between adjacent corneal layers. In one embodiment, the nutrient transport structure  116  is configured to prevent depletion of more than about 4 percent of glucose (or other biological substance) in adjacent tissue of at least one of the first corneal layer and the second corneal layer. 
     The holes  120  may be configured to maintain the transport of nutrients across the mask  100 . In one embodiment, the holes  120  are formed with a diameter of about 0.015 mm or more. In another embodiment, the holes have a diameter of about 0.020 mm. In another embodiment, the holes have a diameter of about 0.025 mm. In another embodiment, the holes have a diameter of about 0.027 mm. In another embodiment, the holes  120  have a diameter in the range of about 0.020 mm to about 0.029 mm. The number of holes in the plurality of holes  120  is selected such that the sum of the surface areas of the hole entrances  140  of all the holes  100  comprises about 5 percent or more of surface area of the anterior surface  108  of the mask  100 . In another embodiment, the number of holes  120  is selected such that the sum of the surface areas of the hole exits  164  of all the holes  120  comprises about 5 percent or more of surface area of the posterior surface  112  of the mask  100 . In another embodiment, the number of holes  120  is selected such that the sum of the surface areas of the hole exits  164  of all the holes  120  comprises about 5 percent or more of surface area of the posterior surface  112  of the mask  112  and the sum of the surface areas of the hole entrances  140  of all the holes  120  comprises about 5 percent or more of surface area of the anterior surface  108  of the mask  100 . In another embodiment, the plurality of holes  120  may comprise about 1600 microperforations. 
     Each of the holes  120  may have a relatively constant cross-sectional area. In one embodiment, the cross-sectional shape of each of the holes  120  is substantially circular. Each of the holes  120  may comprise a cylinder extending between the anterior surface  108  and the posterior surface  112 . 
     The relative position of the holes  120  is of interest in some embodiments. As discussed above, the holes  120  of the mask  100  are hex-packed, e.g., arranged in a hex pattern. In particular, in this embodiment, each of the holes  120  is separated from the adjacent holes  120  by a substantially constant distance, sometimes referred to herein as a hole pitch. In one embodiment, the hole pitch is about 0.045 mm. 
     In a hex pattern, the angles between lines of symmetry are approximately 43 degrees. The spacing of holes along any line of holes is generally within the range of from about 30 microns to about 100 microns, and, in one embodiment, is approximately 43 microns. The hole diameter is generally within the range of from about 10 microns to about 100 microns, and in one embodiment, is approximately 20 microns. The hole spacing and diameter are related if you want to control the amount of light coming through. The light transmission is a function of the sum of hole areas as will be understood by those of skill in the art in view of the disclosure herein. 
     The embodiment of  FIG. 43  advantageously enables nutrients to flow from the first corneal layer to the second corneal layer. The inventors have discovered that negative visual effects can arise due to the presence of the transport structure  116 . For example, in some cases, a hex packed arrangement of the holes  120  can generate diffraction patterns visible to the patient. For example, patients might observe a plurality of spots, e.g., six spots, surrounding a central light with holes  120  having a hex patterned. 
     The inventors have discovered a variety of techniques that produce advantageous arrangements of a transport structure such that diffraction patterns and other deleterious visual effects do not substantially inhibit other visual benefits of a mask. In one embodiment, where diffraction effects would be observable, the nutrient transport structure is arranged to spread the diffracted light out uniformly across the image to eliminate observable spots. In another embodiment, the nutrient transport structure employs a pattern that substantially eliminates diffraction patterns or pushes the patterns to the periphery of the image. 
       FIGS. 45B-45C  show two embodiments of patterns of holes  220  that may be applied to a mask that is otherwise substantially similar to the mask  100 . The holes  220  of the hole patterns of  FIGS. 45B-45C  are spaced from each other by a random hole spacing or hole pitch. In other embodiments discussed below, holes are spaced from each other by a non-uniform amount, e.g., not a random amount. In one embodiment, the holes  220  have a substantially uniform shape (cylindrical shafts having a substantially constant cross-sectional area).  FIG. 45C  illustrates a plurality of holes  220  separated by a random spacing, wherein the density of the holes is greater than that of  FIG. 45B . Generally, the higher the percentage of the mask body that has holes the more the mask will transport nutrients in a manner similar to the native tissue. One way to provide a higher percentage of hole area is to increase the density of the holes. Increased hole density can also permit smaller holes to achieve the same nutrient transport as is achieved by less dense, larger holes. 
       FIG. 46A  shows a portion of another mask  200   a  that is substantially similar to the mask  100 , except described differently below. The mask  200   a  can be made of any of the materials discussed herein. The mask  200   a  can be formed by any suitable process, such as those discussed below with variations of such processes. The mask  200   a  has a nutrient transport structure  216   a  that includes a plurality of holes  220   a . A substantial number of the holes  220   a  have a non-uniform size. The holes  220   a  may be uniform in cross-sectional shape. The cross-sectional shape of the holes  220   a  is substantially circular in one embodiment. The holes  220   a  may be circular in shape and have the same diameter from a hole entrance to a hole exit, but are otherwise non-uniform in at least one aspect, e.g., in size. It may be preferable to vary the size of a substantial number of the holes by a random amount. In another embodiment, the holes  220   a  are non-uniform (e.g., random) in size and are separated by a non-uniform (e.g., a random) spacing. 
       FIG. 46B  illustrates another embodiment of a mask  200   b  that is substantially similar to the mask  100 , except as described differently below. The mask  200   b  can be made of any of the materials discussed herein. Also, the mask  200   b  can be formed by any suitable process, such as those discussed below with variations of such processes. The mask  200   b  includes a body  204   b . The mask  200   b  has a transport structure  216   b  that includes a plurality of holes  220   b  with a non-uniform facet orientation. In particular, each of the holes  220   b  has a hole entrance that may be located at an anterior surface of the mask  200   b . A facet of the hole entrance is defined by a portion of the body  204   b  of the mask  200   b  surrounding the hole entrance. The facet is the shape of the hole entrance at the anterior surface. In one embodiment, most or all the facets have an elongate shape, e.g., an oblong shape, with a long axis and a short axis that is perpendicular to the long axis. The facets may be substantially uniform in shape. In one embodiment, the orientation of facets is not uniform. For example, a substantial number of the facets may have a non-uniform orientation. In one arrangement, a substantial number of the facets have a random orientation. In some embodiments, the facets are non-uniform (e.g., random) in shape and are non-uniform (e.g., random) in orientation. 
     Other embodiments may be provided that vary at least one aspect, including one or more of the foregoing aspects, of a plurality of holes to reduce the tendency of the holes to produce visible diffraction patterns or patterns that otherwise reduce the vision improvement that may be provided by a mask with an aperture, such as any of those described above. For example, in one embodiment, the hole size, shape, and orientation of at least a substantial number of the holes may be varied randomly or may be otherwise non-uniform. 
       FIG. 47  shows another embodiment of a mask  300  that is substantially similar to any of the masks hereinbefore described, except as described differently below. The mask  300  can be made of any of the materials discussed herein. Also, the mask  300  can be formed by any suitable process, such as those discussed below with variations of such processes. The mask  300  includes a body  304 . The body  304  has an outer peripheral region  305 , an inner peripheral region  306 , and a hole region  307 . The hole region  307  is located between the outer peripheral region  305  and the inner peripheral region  306 . The body  304  may also include an aperture region, where the aperture (discussed below) is not a through hole. The mask  300  also includes a nutrient transport structure  316 . In one embodiment, the nutrient transport structure includes a plurality of holes. At least a substantial portion of the holes (e.g., all of the holes) are located in the hole region  307 . As above, only a portion of the nutrient structure  316  is shown for simplicity. But it should be understood that the holes may be located through the hole region  307 . 
     The outer peripheral region  305  may extend from an outer periphery  324  of the mask  300  to a selected outer circumference  326  of the mask  300 . The selected outer circumference  325  of the mask  300  is located a selected radial distance from the outer periphery  324  of the mask  300 . In one embodiment, the selected outer circumference  325  of the mask  300  is located about 0.05 mm from the outer periphery  324  of the mask  300 . 
     The inner peripheral region  306  may extend from an inner location, e.g., an inner periphery  326  adjacent an aperture  328  of the mask  300  to a selected inner circumference  327  of the mask  300 . The selected inner circumference  327  of the mask  300  is located a selected radial distance from the inner periphery  326  of the mask  300 . In one embodiment, the selected inner circumference  327  of the mask  300  is located about 0.05 mm from the inner periphery  326 . 
     The mask  300  may be the product of a process that involves random selection of a plurality of locations and formation of holes on the mask  300  corresponding to the locations. As discussed further below, the method can also involve determining whether the selected locations satisfy one or more criteria. For example, one criterion prohibits all, at least a majority, or at least a substantial portion of the holes from being formed at locations that correspond to the inner or outer peripheral regions  305 ,  306 . Another criterion prohibits all, at least a majority, or at least a substantial portion of the holes from being formed too close to each other. For example, such a criterion could be used to assure that a wall thickness, e.g., the shortest distance between adjacent holes, is not less than a predetermined amount. In one embodiment, the wall thickness is prevented from being less than about 20 microns. 
     In a variation of the embodiment of  FIG. 47 , the outer peripheral region  305  is eliminated and the hole region  307  extends from the inner peripheral region  306  to an outer periphery  324 . In another variation of the embodiment of  FIG. 47 , the inner peripheral region  306  is eliminated and the hole region  307  extends from the outer peripheral region  305  to an inner periphery  326 . 
       FIG. 44B  shows a mask  400  that is similar to the mask  100  except as described differently below. The mask  400  can be made of any of the materials discussed herein. The mask  400  can be formed by any suitable process, such as those discussed below in connection with variations of such processes. The mask  400  includes a body  404  that has an anterior surface  408  and a posterior surface  412 . The mask  400  also includes a nutrient transport structure  4316  that, in one embodiment, includes a plurality of holes  420 . The holes  420  are formed in the body  404  so that nutrient transport is provided but transmission of radiant energy (e.g., light) to the retinal locations adjacent the fovea through the holes  404  is substantially prevented. In particular, the holes  404  are formed such that when the eye with which the mask  1000  is coupled is directed at an object to be viewed, light conveying the image of that object that enters the holes  420  cannot exit the holes along a path ending near the fovea. 
     In one embodiment, each of the holes  420  has a hole entrance  460  and a hole exit  464 . Each of the holes  420  extends along a transport axis  466 . The transport axis  466  is formed to substantially prevent propagation of light from the anterior surface  408  to the posterior surface  412  through the holes  420 . In one embodiment, at least a substantial number of the holes  420  have a size to the transport axis  466  that is less than a thickness of the mask  400 . In another embodiment, at least a substantial number of the holes  420  have a longest dimension of a perimeter at least at one of the anterior or posterior surfaces  408 ,  412  (e.g., a facet) that is less than a thickness of the mask  400 . In some embodiments, the transport axis  466  is formed at an angle with respect to a mask axis  436  that substantially prevents propagation of light from the anterior surface  408  to the posterior surface  412  through the hole  420 . In another embodiment, the transport axis  466  of one or more holes  420  is formed at an angle with respect to the mask axis  436  that is large enough to prevent the projection of most of the hole entrance  460  from overlapping the hole exit  464 . 
     In one embodiment, the hole  420  is circular in cross-section and has a diameter between about 0.5 micron and about 8 micron and the transport axis  466  is between 5 and 85 degrees. The length of each of the holes  420  (e.g., the distance between the anterior surface  408  and the posterior surface  412 ) is between about 8 and about 92 micron. In another embodiment, the diameter of the holes  420  is about 5 micron and the transport angle is about 40 degrees or more. As the length of the holes  420  increases it may be desirable to include additional holes  420 . In some cases, additional holes  420  counteract the tendency of longer holes to reduce the amount of nutrient flow through the mask  400 . 
       FIG. 44C  shows another embodiment of a mask  500  similar to the mask  100 , except as described differently below. The mask  500  can be made of any of the materials discussed herein. The mask  500  can be formed by any suitable process, such as those discussed below with variations of such processes. The mask  500  includes a body  504  that has an anterior surface  508 , a first mask layer  510  adjacent the anterior surface  508 , a posterior surface  512 , a second mask layer  514  adjacent the posterior surface  512 , and a third mask layer  515  located between the first mask layer  510  and the second mask layer  514 . The mask  500  also includes a nutrient transport structure  516  that, in one embodiment, includes a plurality of holes  520 . The holes  520  are formed in the body  504  so that nutrient are transported across the mask, as discussed above, but transmission of radiant energy (e.g., light) to retinal locations adjacent the fovea through the holes  520  is substantially prevented. In particular, the holes  520  are formed such that when the eye with which the mask  500  is coupled is directed at an object to be viewed, light conveying the image of that object that enters the holes  520  cannot exit the holes along a path ending near the fovea. 
     In one embodiment, at least one of the holes  520  extends along a non-linear path that substantially prevents propagation of light from the anterior surface to the posterior surface through the at least one hole. In one embodiment, the mask  500  includes a first hole portion  520   a  that extends along a first transport axis  566   a , the second mask layer  514  includes a second hole portion  520   b  extending along a second transport axis  566   b , and the third mask layer  515  includes a third hole portion  520   c  extending along a third transport axis  566   c . The first, second, and third transport axes  566   a ,  566   b ,  566   c  preferably are not collinear. In one embodiment, the first and second transport axes  566   a ,  566   b  are parallel but are off-set by a first selected amount. In one embodiment, the second and third transport axes  566   b ,  566   c  are parallel but are off-set by a second selected amount. In the illustrated embodiment, each of the transport axes  566   a ,  566   b ,  566   c  are off-set by one-half of the width of the hole portions  520   a ,  520   b ,  520   c . Thus, the inner-most edge of the hole portion  520   a  is spaced from the axis  536  by a distance that is equal to or greater than the distance of the outer-most edge of the hole portion  520   b  from the axis  536 . This spacing substantially prevents light from passing through the holes  520  from the anterior surface  508  to the posterior surface  512 . 
     In one embodiment, the first and second amounts are selected to substantially prevent the transmission of light therethrough. The first and second amounts of off-set may be achieved in any suitable fashion. One technique for forming the hole portions  520   a ,  520   b ,  520   c  with the desired off-set is to provide a layered structure. As discussed above, the mask  500  may include the first layer  510 , the second layer  514 , and the third layer  515 .  FIG. 44C  shows that the mask  500  can be formed with three layers. In another embodiment, the mask  500  is formed of more than three layers. Providing more layers may advantageously further decrease the tendency of light to be transmitted through the holes  490  onto the retina. This has the benefit of reducing the likelihood that a patient will observe or otherwise perceive a pattern that will detract from the vision benefits of the mask  500 . A further benefit is that less light will pass through the mask  500 , thereby enhancing the depth of focus increase due to the pin-hole sized aperture formed therein. 
     In any of the foregoing mask embodiments, the body of the mask may be formed of a material selected to provide adequate nutrient transport and to substantially prevent negative optic effects, such as diffraction, as discussed above. In various embodiments, the masks are formed of an open cell foam material. In another embodiment, the masks are formed of an expanded solid material. 
     As discussed above in connection with  FIGS. 45B and 45C , various random patterns of holes may advantageously be provided for nutrient transport. In some embodiment, it may be sufficient to provide regular patterns that are non-uniform in some aspect. Non-uniform aspects to the holes may be provided by any suitable technique. 
     In a first step of one technique, a plurality of locations  220 ′ is generated. The locations  220 ′ are a series of coordinates that may comprise a non-uniform pattern or a regular pattern. The locations  220 ′ may be randomly generated or may be related by a mathematical relationship (e.g., separated by a fixed spacing or by an amount that can be mathematically defined). In one embodiment, the locations are selected to be separated by a constant pitch or spacing and may be hex packed. 
     In a second step, a subset of the locations among the plurality of locations  220 ′ is modified to maintain a performance characteristic of the mask. The performance characteristic may be any performance characteristic of the mask. For example, the performance characteristic may relate to the structural integrity of the mask. Where the plurality of locations  220 ′ is selected at random, the process of modifying the subset of locations may make the resulting pattern of holes in the mask a “pseudo-random” pattern. 
     Where a hex packed pattern of locations (such as the locations  120 ′ of  FIG. 45A ) is selected in the first step, the subset of locations may be moved with respect to their initial positions as selected in the first step. In one embodiment, each of the locations in the subset of locations is moved by an amount equal to a fraction of the hole spacing. For example, each of the locations in the subset of locations may be moved by an amount equal to one-quarter of the hole spacing. Where the subset of locations is moved by a constant amount, the locations that are moved preferably are randomly or pseudo-randomly selected. In another embodiment, the subset of location is moved by a random or a pseudo-random amount. 
     In one technique, an outer peripheral region is defined that extends between the outer periphery of the mask and a selected radial distance of about 0.05 mm from the outer periphery. In another embodiment, an inner peripheral region is defined that extends between an aperture of the mask and a selected radial distance of about 0.05 mm from the aperture. In another embodiment, an outer peripheral region is defined that extends between the outer periphery of the mask and a selected radial distance and an inner peripheral region is defined that extends between the aperture of the mask and a selected radial distance from the aperture. In one technique, the subset of location is modified by excluding those locations that would correspond to holes formed in the inner peripheral region or the outer peripheral region. By excluding locations in at least one of the outer peripheral region and the inner peripheral region, the strength of the mask in these regions is increased. Several benefits are provided by stronger inner and outer peripheral regions. For example, the mask may be easier to handle during manufacturing or when being applied to a patient without causing damage to the mask. 
     In another embodiment, the subset of locations is modified by comparing the separation of the holes with minimum and/or maximum limits. For example, it may be desirable to assure that no two locations are closer than a minimum value. In some embodiments this is important to assure that the wall thickness, which corresponds to the separation between adjacent holes, is no less than a minimum amount. As discussed above, the minimum value of separation is about 20 microns in one embodiment, thereby providing a wall thickness of no less than about 20 microns. 
     In another embodiment, the subset of locations is modified and/or the pattern of location is augmented to maintain an optical characteristic of the mask. For example, the optical characteristic may be opacity and the subset of locations may be modified to maintain the opacity of a non-transmissive portion of a mask. In another embodiment, the subset of locations may be modified by equalizing the density of holes in a first region of the body compared with the density of holes in a second region of the body. For example, the locations corresponding to the first and second regions of the non-transmissive portion of the mask may be identified. In one embodiment, the first region and the second region are arcuate regions (e.g., wedges) of substantially equal area. A first areal density of locations (e.g., locations per square inch) is calculated for the locations corresponding to the first region and a second areal density of locations is calculated for the locations corresponding to the second region. In one embodiment, at least one location is added to either the first or the second region based on the comparison of the first and second areal densities. In another embodiment, at least one location is removed based on the comparison of the first and second areal densities. 
     The subset of locations may be modified to maintain nutrient transport of the mask. In one embodiment, the subset of location is modified to maintain glucose transport. 
     In a third step, a hole is formed in a body of a mask at locations corresponding to the pattern of locations as modified, augmented, or modified and augmented. The holes are configured to substantially maintain natural nutrient flow from the first layer to the second layer without producing visible diffraction patterns. 
     Reduction of Visible Diffraction Patterns Produced by Ophthalmic Devices 
     Perforating a corneal inlay to provide nutrient transport can have the disadvantage that light also passes through the holes. Light transmission can reduce the opacity of the annulus to the point of degrading the optical performance of the inlay in some conditions. In dim light conditions for distance vision, increased light transmission through the annulus can increase the overall optical performance by increasing illumination of the retina. While this light may help with distance vision in dim conditions, it may decrease the quality of near vision. Therefore, it is desirable to limit the transmission of light while enhancing transmission of nutrients. 
     The inventors recognized that while nutrient transport through the cornea is largely in the posterior-anterior direction, nutrients also can flow laterally around edges of an inlay. Lateral flow of nutrients can be driven by a gradient of concentration, for example. Thus, even if an impermeable barrier is positioned in a small portion of the cornea, the tissue above the barrier benefits from lateral diffusion, and is not as nutrient-depleted as it would be without lateral diffusion. The closer a region of corneal tissue is to an edge of a nutrient barrier, the less at risk this tissue is to nutrient depletion. Accordingly, an inlay need not have as many perforations at locations near edges as may be at locations farther from edges. Conversely, depletion is at its greatest in the center of a nutrient barrier. Accordingly, there is an advantage to increasing porosity near the center of a nutrient barrier to compensate for the relatively lower lateral flow of nutrients in that central region. Thus, the inlay can be optimized to maintain the health of the cornea. 
     It is possible to design a hole pattern which transmits less light overall, but provides better nutrient transport where it is needed most by creating a gradient of porosity that increases toward a central region of a nutrient blocking structure of an inlay. For example, an arrangement can be provided in which a gradient of porosity is least at the edges and greatest in a central section of an annulus of an inlay. Increasing porosity can be accomplished in a number of ways. For example,  FIG. 52  illustrates an annular corneal inlay  3100  with holes  3102  providing porosity, the holes  3102  being generally randomly arranged, the holes  3102  having substantially the same diameter across the annulus. This pattern could be modified to have a greater number of holes toward a central region of the annulus in some embodiments. While the number of holes toward the central region can be increased, the generally random positioning of the holes is maintained in some embodiments to prevent the holes from producing visible diffraction patterns or other optical artifacts. 
     Other embodiments may be provided that vary at least one aspect of a plurality of holes to reduce the tendency of the holes to produce visible diffraction patterns or patterns that otherwise reduce the vision improvement that may be provided by a mask with an aperture or opening. For example, in one embodiment, the hole size, shape, and orientation of at least a substantial number of the holes may be varied randomly or may be otherwise non-uniform. The mask may also be characterized in that at least one of the hole size, shape, orientation, and spacing of a plurality of holes is varied to reduce the tendency of the holes to produce visible diffraction patterns. In certain embodiments, the tendency of the holes to produce visible diffraction patterns is reduced by having a plurality of the holes having a first hole size, shape, or spacing and at least another plurality of the holes with a second hole size, shape, or spacing different from the first hole size, shape, or spacing. In other embodiments, the mask is characterized in that at least one of the hole size, shape, orientation, and spacing of a substantial number of the plurality of holes is different than at least one of the hole size, shape, orientation, and spacing of at least another substantial number of the plurality of holes to reduce the tendency of the holes to produce visible diffraction patterns. In further embodiments, the holes are positioned at irregular locations. For example, the holes are positioned at irregular locations to minimize the generation of visible artifacts due to the transmission of light through the holes. 
       FIG. 53  illustrates an annular corneal inlay with holes providing porosity for nutrient transport, the holes being generally randomly arranged. The holes in the embodiment of  FIG. 53  are not substantially the same hole diameter across the annulus. Rather, the holes have different hole diameters in different regions of the mask. For example, as discussed in greater detail below, the holes have larger diameters in a central region of the inlay than near the inner and outer circumferences of the inlay to enhance porosity of the inlay toward the central region. Additional hole patterns and arrangements optimized for nutrient flow are discussed in U.S. Pat. No. 7,628,810, U.S. Patent Publication No. 2006-0113054, and U.S. Patent Publication No. 2006-0265058, the entirety of each of which is hereby incorporated by reference. 
     The mask illustrated in  FIG. 52  has an irregular hole pattern with holes that are substantially the same size. In one embodiment, the holes have a diameter of about 10 microns. The embodiment of the mask illustrated in  FIG. 53  has an irregular hole pattern. The mask includes an inner peripheral region neighboring (e.g., immediately adjacent to) the inner periphery of the mask, an outer peripheral region neighboring (e.g., immediately adjacent to) the outer periphery of the mask, and a plurality of annular bands between the inner periphery region and the outer periphery region. The bands can be modified such that there is a generally increasing porosity from at least one of the inner or outer periphery regions toward a central portion of the annulus. For example, in one arrangement, a fixed number of holes is located in each band, with the size of the holes being larger in bands closer to the center of the annulus than in bands that are farther from the center of the annulus. 
       FIG. 54  illustrates an embodiment of a mask  3000  that includes a body  3004  with an aperture or opening  3002 . The body  3004  includes a hole region  3010  between an outer periphery  3012  and an inner periphery  3014  of the body  3004 . The hole region  3010  includes a nutrient transport structure  3030 . Only a portion of the nutrient transport structure  3030  is shown for simplicity. The hole region  3010  can include two more sub-regions, and each sub-region includes a plurality of holes. Each sub-region can have at least one property that is different from at least one property of another sub-region. For example, properties of a sub-region can include average or mean hole size (radius, diameter, area, perimeter, etc.), number of holes per unit area (e.g., hole density), area of holes per unit area (e.g., percentage of sub-region area that includes holes), shape of the holes, spacing between holes, percentage of light transmission, percentage of nutrient depletion, nutrient transport rate (e.g., nutrient transport rate per unit area), or porosity.  FIG. 54  illustrates one embodiment with three sub-regions including an inner region  3020 , an outer region  3022 , and a central region  3024  between the inner region  3020  and the outer region  3022 . The inner region  3020  is located between the inner periphery  3014  and a selected first circumference  3026 , the outer region  3022  is located between the outer periphery  2012  and a selected second circumference  3028 , and the central region is located between the selected first circumference  3026  and the selected second circumference  3028 . Each of the sub-regions can have an area that is the same or different from an area of another sub-regions. For example, each sub-region may or may not be equally spaced radially from the center of the aperture. In certain embodiments, each sub-region is an annular band. 
     As discussed previously, the body  3004  may also include an inner peripheral region  3008  and/or an outer peripheral region  3006  that are substantially devoid of holes. The inner peripheral region  3008  can extend between the inner periphery  3014  and a selected inner circumference  3018 , and the outer peripheral region  3006  can extend between the outer periphery  3012  and a selected outer circumference  3016 . 
     Nutrient depletion can be greatest near the center of the annulus (e.g., about midway between the outer periphery  3012  and the inner periphery  3014 . Therefore, more hole area or porosity that allows nutrient transport through the mask  3000  near the center of the annulus can decrease nutrient depletion caused by the mask  3000 . In certain embodiments, the central region  3024  has a greater ability to transport nutrients than the inner region  3020  and/or the outer region  3022 . For example, the central region  3024  has a central area and the plurality of holes in the central region  3024  may comprise a first percentage of the central area. Similarly, the inner region  3020  has an inner area and the plurality of holes in the inner region  3020  may comprise a second percentage of the inner area, and the outer region  3022  has an outer area and the plurality of holes in the outer region  3022  may comprise a third percentage of the outer area. The first percentage can be greater than the second percentage and/or the third percentage. In another example, the central region  3024  may include a first porosity, the inner region  3020  may include a second porosity, the outer region  3024  may include a third porosity, and the first porosity is greater than the second porosity and/or the third porosity. In other words, the central region  3024 , the inner region  3020 , and the outer region  3022  can include a nutrient transport property that improves nutrient transport through the mask  3000 . The central region  3024  can include a first nutrient transport property value, the inner region  3020  can include a second nutrient transport property value, the outer region  3022  can include a third nutrient transport property value, and the first nutrient transport property value can be greater than the second and/or third nutrient transport property value. The nutrient transport property can be, for example, porosity, hole percentage, hole size, number of holes per unit area, or nutrient transport rate. 
     The position of the sub-regions can have a variety of configurations. In certain embodiments, the central region is located at between about 10 to about 90 percent of the annular width of the mask from the inner periphery. In additional embodiments, the central region is located at between about 20 to about 60 percent, between about 30 and about 50 percent, or between about 30 and 40 percent of the annular width of the mask from the inner periphery. 
     The hole region  3010  may also include more than three regions (e.g., inner, outer, and central regions) that are described above. The hole region  3010  can include any number of regions from two to infinity. For example, the hole region  3010  can gradually change one or properties radially across the mask body  3004  and may not change in a step fashion. In one embodiment, the porosity increases and then decreases radially from the inner periphery to the outer periphery. For example, the porosity may be substantially zero at or near the inner periphery and gradually increase to a maximum porosity and then gradually decrease to be substantially zero at or near the outer periphery. 
     In one arrangement, as illustrated in  FIG. 53 , ten annular bands are disposed between the inner periphery region and the outer periphery region. The first band of the ten annular bands neighbors (e.g., is immediately adjacent to) the inner periphery region, the second band neighbors the first band, and so forth. The tenth band neighbors the outer periphery region. Each band includes 840 holes in one embodiment. The inner periphery region and outer periphery region can take any suitable form, but preferably include no holes. The radial width of the size of inner periphery region and outer periphery region can be any suitable width, for example optimized to maintain the mechanical integrity of the inlay or to provide for handling by a user. In one embodiment, the inner periphery region and outer periphery region are 50 about microns wide. In some embodiments, only one of the inner periphery region and outer periphery region is provided. In other words, one of the bands with holes can be located at the inner periphery or the outer periphery. 
     One embodiment is further described in Table I. Each of the bands has a band width, a percentage of light transmission through the band, and a hole diameter for the holes in the band, as illustrated in Table I. In the embodiment of Table I, the bands are configured to be of equal area, and thus have progressively smaller widths farther from the inner periphery of the inlay. However, annular bands can be provided with different areas between the inner periphery and the outer periphery in some embodiments. 
     
       
         
           
               
             
               
                 TABLE I 
               
             
            
               
                   
               
               
                 Properties of one embodiment of the inlay of FIG. 53. 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Band 
                 Hole Diameter 
                 % 
                 Band Width 
               
               
                   
                 No. 
                 (microns) 
                 Transmission 
                 (microns) 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 1 
                 5.45 
                 2.3 
                 146 
               
               
                   
                 2 
                 7.45 
                 4.3 
                 127 
               
               
                   
                 3 
                 9.45 
                 6.9 
                 114 
               
               
                   
                 4 
                 11.45 
                 10.2 
                 105 
               
               
                   
                 5 
                 10.45 
                 8.5 
                 97 
               
               
                   
                 6 
                 9.45 
                 6.9 
                 91 
               
               
                   
                 7 
                 8.45 
                 5.6 
                 86 
               
               
                   
                 8 
                 7.45 
                 4.3 
                 81 
               
               
                   
                 9 
                 6.45 
                 3.2 
                 78 
               
               
                   
                 10 
                 5.45 
                 2.3 
                 74 
               
               
                   
                   
               
            
           
         
       
     
     In some embodiments, the central portion of the light blocking portion of the inlay (e.g., a midline of the annulus) is farthest from a source of lateral nutrient flow. In such an embodiment, it may be desirable to locate the portion (e.g., the band) of greatest porosity at or around the central portion. In other embodiments, the peak porosity can be located between the mid-line of the annulus and the inner periphery. In some applications of a small aperture inlay, lateral flow emanating from the aperture at the inner periphery of the inlay and propagating outward through corneal tissue anterior and/or posterior of the annulus is expected to be less than lateral flow emanating from tissue radially outward of the outer periphery and propagating inward through corneal tissue anterior and/or posterior of the annulus. In one embodiment, the location of peak porosity is at about 40 percent or less of the annular width of the inlay from the inner periphery. Such an arrangement provides a higher percentage of total nutrient flow to tissue anterior and/or posterior of an inner portion of the annulus from the nutrient flow structure than is provided to similar tissue adjacent to an outer portion of the annulus. 
     In the embodiment of the inlay of  FIG. 53  described by Table I, the modeled average light transmission is about 5%. In the embodiment of the inlay of  FIG. 52 , the modeled average light transmission is about 6.75%. The inlays of  FIGS. 52 and 53  have an inner radius of 0.8 mm (e.g., an aperture with a diameter of 1.6 mm), and an outer radius of 1.9 mm (e.g., radial distance from the center of the aperture to the outer periphery of the inlay. 
       FIG. 55  illustrates a comparison of modeled glucose depletion in a cornea in which the inlays of  FIGS. 52 and 53  have been implanted as a function of radial distances from the center of the inlay or aperture.  FIG. 55  was obtained from a finite-element model of glucose transport in the human cornea. The inlays of  FIGS. 52 and 53  extend from the inner periphery at a radial distance of 0.8 mm to the outer periphery at a radial distance of 1.9 mm. The radial distance from the center of the aperture plotted in  FIG. 55  starts at 0 mm (e.g., center of the aperture) and goes to greater than 1.9 mm (e.g., greater than the outer periphery of the inlay). From  FIG. 55 , it is clear that increasing the porosity, in this case, by increasing the size of holes near the annulus midline, can reduce glucose depletion. In particular,  FIG. 55  shows that the embodiment of  FIG. 53  reduces depletion of glucose while at the same time decreasing the overall porosity or hole density from 6.75% to 5%. The reduced light transmission of the mask of  FIG. 53  compared to the mask of  FIG. 52  improves the visual acuity produced by the mask. Therefore, advantageously, the mask of  FIG. 53  has both improved nutrient transport and visual acuity compared to the mask of  FIG. 52 . 
     Material Bridging an Ophthalmic Device 
     As discussed above, the mask can include a plurality of holes. Lens body material can extend at least partially through the holes, thereby creating a bond (e.g. material “bridge”) between the lens body portion on either side of the mask. 
     The holes  120  of the mask  100  shown in  FIG. 43  may be located anywhere on the mask  100 . Substantially all of the holes can be in one or more regions of a mask. The holes  120  of  FIG. 43  extend at least partially between the anterior surface  108  and the posterior surface  112  of the mask  100 . Each of the holes  120  can include a hole entrance  160  and a hole exit  164 . The hole entrance  160  is located adjacent to the anterior surface  108  of the mask  100 . The hole exit  164  is located adjacent to the posterior surface  112  of the mask  100 . Each of the holes  120  can extend the entire distance between the anterior surface  108  and the posterior surface  112  of the mask  100 . Further details about possible hole patterns are described in WO 2011/020074, filed Aug. 13, 2010, which is incorporated by reference in its entirety. 
     The mask  100  can include an annular region near the outer periphery  124  of the mask having no holes. In certain embodiments, there are no holes within 0.1 mm of the outer periphery  124  of the mask  100 . 
     The mask can include an annular region around the inner periphery of the mask having no holes. In certain embodiments, there are no holes within 0.1 mm of the aperture  128 . 
     As shown in  FIG. 56 , the mask  2100  can include a plurality of holes  2120 . In some embodiments, the holes  2120  each have a same diameter or one or more different diameters. In some embodiments, the holes  2120  can include at least four different diameter. 
     The diameter of any single hole  2120  is at least about 0.01 mm and/or less than or equal to about 0.02 mm. In some embodiments, the diameter of the holes  2120  can include one or more of the following hole diameters: 0.010 mm, 0.013 mm, 0.016 mm, and/or 0.019 mm. 
     There are at least about 1000 holes and/or less than or equal to about 2000 holes. In some embodiments, there are at least about 1000 holes and/or less than or equal to about 1100 holes. In some embodiments, there are about 1040 holes. In some embodiments, there are an equal number of holes of each diameter. In some embodiments, the number of holes having each diameter is different. 
     The holes can be dispersed throughout at least a portion of the mask  2100 . The holes are dispersed at irregular locations and/or evenly dispersed randomly throughout a hole region of the mask  2100 . 
     The hole region can be the entire mask  2100  or only a portion of the mask  2100  and include a plurality of sub-regions. The surface area of combined sub-regions is the same as the surface area of the hole region or the sub-regions can overlap each other. Each sub-region can be the same shape and/or cover the same surface area of the hole region, or each sub-region can have a different shape and/or different size. 
     The holes can be randomly dispersed such that two hole sizes having the same diameter are not located within the same sub-region of the hole region. Also, The holes can be randomly dispersed across a hole region to substantially minimize the appearance diffraction patterns. The hole sizes can be evenly dispersed such that the integrity of the bond between the lens body portions on either side of the mask is substantially constant across the mask. 
     The plurality of holes  2120  can include at least two different hole sizes. Each sub-region of the hole region can include one hole having each hole size. The number of holes in each sub-region can be the same as the number of different hole diameters. The holes can be randomly dispersed within each subregion, such that the position of the holes in a first sub-region is different from the position of the holes in a second sub-region. 
     The plurality of holes  2120  can include four different hole sizes. Each sub-region of the hole region can include four holes, each of the holes having a different diameter. 
     Intraocular Implants with Reduced Thickness 
     The natural lens of an eye is often replaced with an intraocular lens when the natural lens has been clouded over by a cataract. An intraocular lens may also be implanted into the eye to correct other refractive defects without removing the natural lens. The intraocular implant can include any of the mask embodiments discussed herein. The intraocular implants may be implanted in the anterior chamber or the posterior chamber of the eye. In the posterior chamber, the implants may be fixated in the ciliary sulcus, in the capsular bag, or anywhere an intraocular implant is fixated. The intraocular lenses can have a reduced thickness in a central region compared to conventional intraocular lenses. The reduced thickness in the central region can help improve implantation of the intraocular lens. 
     Several alternatives to fixed-focus IOLs have been developed, including multifocal IOLs and accommodating IOLs that attempt to provide the ability to see clearly at both distance and near. Multifocal IOLs do provide good acuity at both distance and near, but these lenses typically do not perform well at intermediate distances and are associated with glare, halos, and night vision difficulties associated with the presence of unfocused light. Accommodating IOLs of several designs have also been developed, but none so far has been able to replicate the function of the natural crystalline lens. IOLs with apertures have been described by Vorosmarthy (U.S. Pat. No. 4,976,732). These devices, however, do not attempt to change focus from far to near, but merely attempt to reduce the blurry image from defocus to a level where a presbyopic emmetrope can read. Notably, Vorosmarthy did not address the issue of reducing thickness of a masked IOL for application in small-incision surgery. 
     The masked IOL can include a thinner optic than has been known in the art. The advantage to a thinner optic is that the IOL can be inserted through a smaller incision into the eye. Since corneal incisions tend to distort the cornea and impair vision, reducing the size of the incision will improve the quality of vision. The optic is made thinner by means similar to a Fresnel lens, where alternating concentric zones provide focusing power and height steps. While the thickness reduction possible with a Fresnel lens is significant, the height steps are optically inappropriate for clinical application. They do not focus light to an image at the fovea, but instead scatter light, leading to dysphotopsias (streaks, shadows, halos, etc.) in the patient&#39;s vision. By combining Fresnel-type height steps with a mask that blocks light from passing through the steps and allows light to pass only through the focusing surfaces, one can eliminate the dysphotopsias associated with a common Fresnel lens, obtaining the benefit of reduced thickness without introducing unwanted optical effects. 
     Generally, intraocular implants are implanted into the eye by rolling up an intraocular implant and inserting the rolled up intraocular implant into a tube. The tube is inserted into an incision in the eye, and the intraocular implant is ejected out of the tube and deployed within the eye. Intraocular implants can be implanted within the lens capsule after removal of the natural lens, or in the anterior chamber, posterior chamber, and can be coupled with or attached to the ciliary sulcus (sometimes referred to herein as “sulcus-fixated”). Depending on the location of the intraocular implant within the eye, dimensions of the intraocular implant, including but not limited to the aperture of the mask, may be adjusted. By reducing the thickness of in the central region of the intraocular lens, the intraocular lens can be rolled up tighter and inserted into a smaller tube. A smaller incision can be made in the eye if a smaller tube is used. The result is a less invasive procedure with quicker recovery time for the patient. Also, compared with a conventional posterior chamber phakic intraocular lens, a reduced thickness lens that is fixated in the ciliary sulcus will allow more space between the intraocular lens posterior surface and the natural crystalline lens surface, thereby reducing the potential for contact between these surfaces. 
     The intraocular lens  4100  can include a lens body  4102  with an optical power to refract light and correct refractive errors of the eye. The intraocular lens  100  may include one or more haptics  4104  to prevent the intraocular lens  4100  from moving or rotating within the eye. As used herein the term “haptic” is intended to be a broad term encompassing struts and other mechanical structures that can be apposed against an inner surface of an eye and mounted to a lens structure to securely position a lens in an optical path of an eye. The haptics  4104  can be a variety of shapes and sizes depending on the location the intraocular lens  4100  is implanted in the eye. Haptics illustrated in  FIGS. 57-66  can be interchanged with any variety of haptic. Haptics may be C-shaped, J-shaped, plate design, or any other design. An intraocular implant described herein may have two, three, four, or more haptics. The haptics may be of open or closed configuration and may be planar, angled, or step-vaulted. Examples of haptics are disclosed in U.S. Pat. Nos. 4,634,442; 5,192,319; 6,106,553; 6,228,115; Re.  34 , 251 ;  7 , 455 , 691 ; and U.S. Patent Application Publication 2003/0199978, which are incorporated in their entirety by reference. 
     The lens body  4102  can include a posterior surface  4110  and an anterior surface  4112 , as illustrated in  FIGS. 57A-B . The lens body  4102  includes a first portion  4116  (e.g., inner portion or central region), a second portion  4114  (e.g., transition zone) and a third portion  4118  (e.g., outer portion or region) on the posterior surface  4110 . The second portion  4114  can be between and/or adjacent the first portion  4116  and the third portion  4118 . The second portion  4114  can substantially surround the first portion  4116 , and the third portion  4118  can substantially surround the second portion  4114 . The first portion  4116  can be substantially circular, and the second portion  4114  and third portion  4118  can be substantially annular. The first portion  4116  and third portion  4118  can refract light or have an optical power to improve a patient&#39;s vision. The second portion  4114  has one or more facets, grooves, crests, troughs, depressions, contours, surface curvatures, etc. to make the first portion  4116  closer to the anterior surface  4112  than if the posterior surface  4110  did not have the second portion  4114 . The second portion  4114  can also be described as a “transition zone” between the first portion  4116  and the third portion  4118 . For example, the second portion  4114  transition zone can slope toward the anterior surface  4112  from the third portion  4118  to the first portion  4116 . The second portion  4114  transition zone can include a surface substantially perpendicular to the anterior surface  4112 . The transition zones are like those incorporated in a Fresnel lens. They enable the lens body to be made thinner than would be required in a conventional lens design. However, as with Fresnel lenses, the transition zones introduce optical aberrations that would not be clinically acceptable in intraocular lenses. 
     The intraocular lens  4100  can include a mask  4108  that can be positioned to block a substantial portion of light that would pass through the second portion  4114  transition zone of the posterior surface  4110 . “Blocked” as used in this context includes preventing at least a portion of light from passing through the mask, as well as preventing substantially all the light from passing through the mask. If the mask  4108  did not block the light rays that would pass through the second portion  4114 , aberrations would result since the refraction of light (e.g. optical power, etc.) in the second portion  4114  is typically different than in the first portion  116  and the third portion  4118 . 
     The first portion  4116  can be convex, the second portion  4114  can be concave, and the third portion  4118  can convex. The first portion  4116  and the third portion  4118  can have a positive or converging optical power and the second portion  4114  can have a negative or diverging optical power. The second portion  4114  may have curvature or no curvature in a direction extending radially from the first portion  4116  to the third portion  4118 . For example, the second portion  4114  may have a positive or negative curvature (e.g., convex or concave) in a direction extending radially from the first portion  4116  to the third portion  4118 . Furthermore, the second portion  4114  may form a closed loop and have surface similar to an outer surface of a frustoconical shape. 
     In certain embodiments, the first portion  116  is within a central region  132  of the lens body  102 . The central region  132  can be recessed within the lens body  102 . In certain embodiments, the third portion  118  is within an outer region  130  of the lens body  102 . In certain embodiments, an outer perimeter of the first portion  116  is surrounded and/or enclosed by an inner perimeter of the second portion  114 . In certain embodiments, an outer perimeter of the second portion  114  is surrounded and/or enclosed by an inner perimeter of the third portion  118 . In certain embodiments, the maximum thickness of the lens body  102  in the region of the first portion  116  is less than the maximum thickness of the lens body  102  in the region of the second portion  114 . 
     A lens body  4202  can include a first portion  4222 , a second portion  4220  and a third portion  4224  on the anterior surface  4212 , as illustrated in  FIGS. 58A-B . The first portion  4222 , the second portion  4220  and the third portion  4224  on the anterior surface  4212  can have similar features as described above for the first portion  4116 , the second portion  4114  and the third portion  4118  on the anterior surface  4112 . The intraocular lens  4200  can include a mask  4208  that is positioned to block a substantial portion of light that passes through the second portion  4220  of the anterior surface  4212 . 
     Both an anterior surface  4312  and a posterior surface  4310  can have a first portion  4316 ,  4322 , a second portion  4314 ,  4320  and a third portion  4318 ,  4324 , as illustrated in  FIGS. 59A-B . A mask  4308  can be positioned so that a substantial portion of the light that passes through the second portion  4320  of the anterior surface  4312  and the light that would pass through the second portion  4314  of the posterior surface  4310  will be blocked by the mask  4308 . 
     The mask can be coupled with the second portion, which is concave. For example, the mask can be located adjacent the second portion. The mask can be attached to the posterior surface, the anterior surface, the posterior and the anterior surfaces, within the lens body, or between the posterior surface and the anterior surface. The radial width or the area of the mask can be about the same as the radial width or the area of the second portion. The mask can extend at least partially into the area of the first portion and/or the third portion of the lens body. By extending the mask into the first portion and/or the third portion, the mask can block light that enters at large angles off the optical center axis of the lens body and that may then pass through the second portion. 
     Illustrated in  FIGS. 60A-B , an intraocular lens  4400  can further include a fourth portion  4420   b  and a fifth portion  4424   b  on the anterior surface  4412  and/or the posterior surface  4410 . The fourth portion  4420   b  is adjacent the third portion  4424   a  and can substantially surround the third portion  4424   a . The fifth portion  4424   b  is adjacent the fourth portion  4420   b  and can substantially surround the fourth portion  4420   b . The fourth portion  4420   b  can have similar features as described above for the second portion  4420   a , and the fifth portion  4424   b  can have similar features as described above for the third portion  4424   a . The intraocular lens  4400  can include a first mask  4408   a  that is positioned to block a substantial portion of light that passes through the second portion  4420   a  of the anterior surface  4412 , and a second mask  4408   b  that is positioned to block a substantial portion of light that passes through the fourth portion  4420   b  of the anterior surface  4412 . It should be understood that additional pairs of portions with a mask like the fourth portion  4420   b , the fifth portion  4424   b  and the second mask  4408   b  can be further included in an intraocular lens. 
       FIGS. 61A-B  illustrate an intraocular lens  4500  similar to the intraocular lens  4400  illustrated in  FIGS. 60A-B . Instead of the intraocular lens  4400  having a first mask  4408   a  and a second mask  4408   b , the intraocular lens  4500  has a single mask  4508  with a plurality of light transmission holes that allow at least partial light transmission through the mask  4508 . The light transmission holes can be configured to allow substantially no light that passes through the second portion  4520   a  and the fourth portion  4520   b  to pass through the mask  4508 , but allow at least some light that passes through the third portion  4524   a  to pass through the mask  4508 . For example, a middle annular region of the mask can have a plurality of holes to allow at least some light to pass through the mask, and an inner annular region and an outer annular region can have substantially no holes. Light transmission structures or holes are further discussed in sections below and can be applied to embodiments discussed herein. 
     The variety of intraocular lenses described herein are designed to suit the vision correction needs of particular patients. For example, for patients with relatively small pupils, dim light may present more of a vision issue than for patients with larger pupils. For smaller pupil patients, a mask with more light transmission and/or a smaller outer diameter will increase the amount of light that reaches the retina and may improve vision in dim light situations. Conversely, for larger pupil patients, less light transmission and/or a larger outer diameter mask may improve low-contrast near vision and block more unfocused light. The masked IOLs described herein give the surgeon flexibility to prescribe the appropriate combination of masked IOL features for particular patients. 
       FIGS. 62-63  illustrate intraocular lenses  4600 ,  4700 . The posterior surface and anterior surface of an intraocular lens can have a variety of curvatures. For example, the posterior surface and/or the anterior surface can be concave or convex.  FIGS. 62A-B  illustrates an intraocular lens  4600  with a concave posterior surface  4610  with an anterior surface  4612  to create a positive optical power lens.  FIGS. 63A-B  illustrate an intraocular lens  4700  with a concave posterior surface  4710  with an anterior surface  4712  to create a negative optical power lens. Both intraocular lenses  4600 ,  4700  have a second portion  4620 ,  4720  to reduce the overall thickness of the intraocular lenses  4600 ,  4700 . Both intraocular lenses  4600 ,  4700  also can include a mask  4608 ,  4708  to block light that passes through the second portion  4620 ,  4720 . For negative power intraocular lenses, such as the intraocular lens  4700  of  FIG. 63 , the thickness of the central region  4732  of the lens body  4702  may not be reduced by the second portion  4720 . However, the thickness of the outer region  4730  of the lens body  4702  can be reduced by the second portion  4720  (e.g., transition zone). Advantageously, if an intraocular lens has a positive optical power or a negative optical power, the thickness of at least a portion of the lens body can be reduced by having the lens body include a second portion. 
     Tables II and III illustrate examples of intraocular lens with reduced lens body thicknesses. The column labeled “Reduced” corresponds to an intraocular lens with a second portion (e.g. transition zone), and the column labeled “Original” is corresponds to an intraocular lens without a second portion. The optic diameter is the diameter of the outer-most portion of the lens body with an optical power. The reduction percentage of the center region thickness indicated in Tables II and III can be about proportional to the reduction in the possible rolled up diameter of a reduced thickness IOL. Therefore, the reduction percentage of the center region thickness indicated in Tables II and III can also be about proportional to the reduction in the incision size that can be used during implantation of the IOL in a patient. An IOL is rolled up and inserted into a tube, and the tube is inserted into the incision. The IOL can then be deployed into the intraocular space of the eye. The IOL is often rolled up as tight as possible so that open space (e.g., voids) is minimized in a cross-section of the tube at a location where the implant body has the greatest cross-sectional area that is generally parallel with the optical axis of the implant body. Therefore, the cross-sectional area of the tube is greater than or equal to the greatest cross-sectional area of the implant body that is generally parallel with the optical axis of the implant body. For example, a 36% reduction in the cross sectional area of the implant body could reduce the cross sectional area of the tube by 36% or could reduce the diameter of the tube by about 20%. A minimum incision length is generally one-half of the circumference of the tube. Therefore, a 36% reduction in the cross sectional area of the implant body can result in about 20% reduction in incision length. For example, a 1.8 mm incision could be reduced to about 1.44 mm. A smaller incision is beneficial because it avoids post-operative astigmatism. 
     
       
         
           
               
             
               
                 TABLE II 
               
             
            
               
                   
               
               
                 EXAMPLES OF REDUCED THICKNESS IOLS 
               
               
                 WITH POSITIVE OPTICAL POWER. 
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                   
                 Center region thickness 
                 Cross section area of center 
               
               
                 Optic 
                 Material 
                   
                 [mm] 
                 region [mm 2 ] 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 Diameter 
                 [Ref. 
                   
                   
                   
                 Reduction 
                   
                   
                 Reduction 
               
               
                 [mm] 
                 index] 
                 Diopter 
                 Original 
                 Reduced 
                 [%] 
                 Original 
                 Reduced 
                 [%] 
               
               
                   
               
            
           
           
               
            
               
                 Biconvex IOL 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 5.5 
                 1.4300 
                 18.0 
                 0.94 
                 0.42 
                 55 
                 3.96 
                 2.48 
                 37 
               
               
                 5.5 
                 1.4300 
                 24.0 
                 1.20 
                 0.56 
                 53 
                 4.93 
                 3.13 
                 37 
               
               
                 5.5 
                 1.4583 
                 18.0 
                 0.77 
                 0.32 
                 58 
                 3.32 
                 2.05 
                 38 
               
               
                 5.5 
                 1.4583 
                 24.0 
                 0.96 
                 0.42 
                 56 
                 4.02 
                 2.51 
                 38 
               
               
                 6.0 
                 1.4300 
                 18.0 
                 1.08 
                 0.50 
                 54 
                 4.76 
                 3.08 
                 35 
               
               
                 6.0 
                 1.4300 
                 24.0 
                 1.40 
                 0.62 
                 56 
                 6.04 
                 3.85 
                 36 
               
               
                 6.0 
                 1.4583 
                 18.0 
                 0.87 
                 0.37 
                 57 
                 3.92 
                 2.50 
                 36 
               
               
                 6.0 
                 1.4583 
                 24.0 
                 1.10 
                 0.50 
                 55 
                 4.88 
                 3.13 
                 36 
               
            
           
           
               
            
               
                 Sulcus-fixated IOL 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 5.5 
                 1.4583 
                 5.0 
                 0.34 
                 0.15 
                 56 
                 1.75 
                 1.22 
                 30 
               
               
                 5.5 
                 1.4583 
                 10.0 
                 0.52 
                 0.20 
                 62 
                 2.43 
                 1.51 
                 38 
               
               
                 6.0 
                 1.4583 
                 5.0 
                 0.37 
                 0.17 
                 54 
                 1.95 
                 1.36 
                 30 
               
               
                 6.0 
                 1.4583 
                 10.0 
                 0.59 
                 0.21 
                 64 
                 2.86 
                 1.76 
                 38 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE III 
               
             
            
               
                   
               
               
                 EXAMPLES OF REDUCED THICKNESS IOLS 
               
               
                 WITH NEGATIVE OPTICAL POWER. 
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                   
                   
                 Cross section area of outer 
               
               
                   
                   
                   
                 Outer region thickness 
                 region 
               
               
                 Optic 
                 Material 
                   
                 [mm] 
                 [mm{circumflex over ( )}2] 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 Diameter 
                 [Ref. 
                   
                   
                   
                 Reduction 
                   
                   
                 Reduction 
               
               
                 [mm] 
                 index] 
                 Diopter 
                 Original 
                 Reduced 
                 [%] 
                 Original 
                 Reduced 
                 [%] 
               
               
                   
               
            
           
           
               
            
               
                 Sulcus-fixated IOL 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 5.5 
                 1.4583 
                 −5.0 
                 0.26 
                 0.17 
                 35 
                 1.09 
                 0.77 
                 29 
               
               
                 5.5 
                 1.4583 
                 −10.0 
                 0.41 
                 0.25 
                 39 
                 1.52 
                 0.97 
                 36 
               
               
                 6.0 
                 1.4583 
                 −5.0 
                 0.29 
                 0.20 
                 31 
                 1.12 
                 0.77 
                 31 
               
               
                 6.0 
                 1.4583 
                 −10.0 
                 0.48 
                 0.32 
                 33 
                 1.57 
                 0.99 
                 37 
               
               
                   
               
            
           
         
       
     
       FIG. 64  illustrates the operation of the intraocular lens  4200  of  FIGS. 58A-B . In use, light enters the anterior surface  4212 , passes through the lens body  4202  and exits the posterior surface  4210  of the intraocular lens  4200 . The mask  4208  is located such that the mask  4208  blocks a substantial portion of the light rays  4850  that pass through the second portion  4220  of the anterior surface  4212 , as illustrated in  FIG. 64 . If the mask  4208  did not block the light rays  4850  that pass through the second portion  4220 , aberrations would result. For example, if the curvature of the second portion  4220  is configured to provide a negative or divergent optical power, light rays  4860  passing through this region would diverge and not focus, as illustrated in  FIG. 64 . The light rays  4850  that pass through the first portion  4222  and/or the third portion  4224  would have a positive or convergent optical power. If the first portion  4222  and the third portion  4224  have a similar curvature or optical power, light rays  4450  entering the anterior surface  4212  and passing through the first portion  4222  and/or the third portion  4224  would converge at a common point  4870  after passing through the posterior surface  4210 , as illustrated in  FIG. 64 .  FIG. 65A  illustrates an intraocular lens  4200  implanted within the capsular bag  4954  of an eye  4952 . Parallel light rays  4950  that pass through the intraocular lens  4200  converge on the retina  4956 . 
     The lens body  4202  can include one or more materials. The lens body  4202  can include two or more materials. For example, the first portion  4222  and the third portion  4224  can include different materials. If the materials selected for the first portion  4222  and the third portion  4224  have different refractive indexes, the curvature of the first portion  4222  and the third portion  4224  can be different to obtain a similar optical power (e.g. dioptric power) for both portions. 
     Generally, the optical power of an intraocular lens is selected for focusing on far objects. A natural lens can deform to change the focal distance for far and near viewing. Conventional artificial intraocular lenses are generally unable to change the focal distance. For example, an eye that is presbyopic or where an artificial intraocular lens has an optical power for farther distance, light rays that enter the eye and pass through the cornea and the natural lens or artificial intraocular lens converge at a point behind or in front of the retina and do not converge at a point on the retina. The light rays strike the retina over a larger area than if the light rays converged at a point on the retina. The patient experiences this as blurred vision, particularly for up-close objects such as when reading. For such conditions, the mask  4208  of the intraocular lens  4200  can be configured with an aperture such that only a subset of light rays, e.g. a central portion, are transmitted to the retina. The mask  4208  with an aperture can improve the depth of focus of a human eye. For example, the aperture can be a pin-hole aperture. The mask  4208  blocks a portion of the outer light rays resulting in more focused light rays. The mask  4208  can include an annular region surrounding an aperture. The aperture can be substantially centrally located on the mask. For example, the aperture can be located around a central axis of the mask, also referred to as the optical axis of the mask. The aperture of the mask can be circular or any other shape. 
     The mask  4208  can be positioned in a variety of locations in or on the intraocular lens  4200 . The mask  4208  can be through the lens body  4202 . The mask  4208  can be positioned on the anterior or posterior surface of the lens body  4202  or embedded within the lens body. For example, the mask  4208  can be positioned substantially at the midway line between the posterior and anterior surfaces of the lens body  4202 , between the midway line and the posterior surface of the lens body  4202 , or between the midway line and the anterior surface of the lens body  4202 . The mask  4208  can be positioned midway, one-third or two-thirds between the midway line and the posterior surface of the lens body  4202 , or the mask can be positioned midway, one-third or two-thirds between the midway line and the anterior surface of the lens body  4202 . If the transition zone is on the anterior surface of the implant body and the mask is positioned to be on or near the surface of the transition zone on the anterior surface, the mask may not extend beyond the transition zone since light even at large angles from the optical axis that hits or passes through the transition zone surface would be blocked by the mask. 
     The mask  4208  of an intraocular lens  4200  can include an aperture wherein the mask blocks a portion of the light to improve viewing near objects, similar to a mask discussed above. Advantageously, the mask  4208  can provide as an aperture and can block a portion light that may not converging on the retina  4956  and also block light that passes through the second portion  4220 , creating aberrations, as described above. In certain embodiments, the aperture of the mask  4208  has a diameter of about 1 to 2 mm. In certain embodiments, the mask  4208  has an outer perimeter with a diameter of about 3 to 5 mm. 
     The third portion  4224  of intraocular lens  4200  can improve low light vision. As the pupil of the eye enlarges, eventually light rays will enter and pass through the third portion  4224  of the intraocular lens  4200 . As illustrated in  FIG. 65 , if the pupil  4958  of the eye  4952  is large enough so that light rays  4950  pass through the third portion  4224  of the intraocular lens  4200 , additional light rays  4950  will strike the retina. As discussed above, the intraocular lens  4200  can have an optical power to correct for viewing far objects so that light rays from a far object are focused at one point on the retina. Near objects during low light conditions may result in an unfocused image if the intraocular lens  4200  has an optical power to view far objects. 
     The mask  4208  can have different degrees of opacity. For example, the mask  4208  can block substantially all of visible light or may block a portion of visible light. The opacity of the mask  4208  may also vary in different regions of the mask  4208 . The opacity of the outer edge and/or the inner edge of the mask  4208  can be less than the central region of the mask  4208 . The opacity in different regions may transition abruptly or have a gradient transition. Additional examples of opacity transitions can be found in U.S. Pat. Nos. 5,662,706, 5,905,561 and 5,965,330, which are incorporated in their entirety by reference. 
     A conventional intraocular lens  5000  is illustrated in  FIGS. 66A-B . By having a recessed portion on the posterior surface  4310  (created by second portions  4314 ) and/or the anterior surface  4312  (created by second portion  4320 ) of the lens body  4302 , the maximum thickness of the intraocular lens  4300  is reduced compared to a conventional lens body  5002  without such portions, as shown in  FIG. 66B . The cross-sectional thickness of the lens body  5002  is generally dependent on the optical power of the intraocular lens  5000  and the material of the lens body  5002 . In particular, the central region of the lens body  5002  is generally the thickest section of the intraocular lens  5000  with a central region cross-sectional thickness  5006 . The lens body  4202  of an intraocular lens  4200  can include a central region thickness  4206  less than the central region thickness  5006  of other common lens bodies. In  FIG. 59B , the thickness  4306  is further reduced compared to a conventional intraocular lens  5000 . 
     Generally, as discussed above, intraocular lenses are implanted into the eye by rolling up an intraocular lens and inserting the rolled up intraocular lens into a tube. One advantage to a thinner lens body is that it the intraocular lens can be more tightly rolled up resulting in being able to use a small tube and a small incision. Another advantage to a thinner lens body is that the intraocular lens can decrease risks associated with implanting in different locations within the eye. For example, an intraocular lens  4200  can be implanted within the anterior chamber. An intraocular lens  4200  can also be positioned within the posterior chamber so that the first portion  4216  of the posterior surface  4210  floats above the natural crystalline lens. The potential for contact between the posterior surface  4210  of the intraocular lens  4200  and the natural crystalline lens will be reduced because the reduced thickness of the intraocular lens  4200 . For example, the intraocular lens  4200  can be coupled with or attached to the ciliary sulcus (sometimes referred to herein as “sulcus-fixated”). An intraocular lens  4200  can also be implanted in the capsular bag, as illustrated in  FIG. 65 . Depending on the location of the intraocular lens within the eye, dimensions of the intraocular lens  4200  including but not limited to the aperture of the mask  4208  may be adjusted. 
     The intraocular lens  4200  and/or the lens body  4202  can be made from one or more materials. For example, the intraocular lens  4200  and/or the lens body  4202  can comprise polymers (e.g. PMMA, PVDF, polypropylene, polycarbonate, PEEK, polyethylene, acrylic copolymers, polystyrene, PVC, polysulfone), hydrogels, and silicone. 
     Near-Ir Transparent Materials 
     As used herein, “substantially opaque,” “blocking substantially all,” or “absorbing substantially all” means blocking or absorbing the transmission of at least about 60%-100% of electromagnetic radiation in the wavelength range or ranges indicated, further including the ranges of at least about 70%-100%, at least about 80%-100%, at least about 90%-100%, and at least about 95%-100%, or any other percentage sufficiently great so as to not impair the depth of focus improvement properties of such masks as are disclosed herein. Also, as used herein, “substantially transparent” or “transmit substantially all” means transmitting or allowing to pass the transmission of at least about 50%-100% of electromagnetic radiation in the wavelength range or ranges indicated, further including the ranges of at least about 60%-100%, at least about 70%-100%, at least about 80%-100%, at least about 90%-100%, at least about 95%-100%, and about 100%, or any other percentage sufficiently great so as to permit NIR imaging of the eye using any NIR imaging modality. 
     Ocular examination and diagnosis is increasingly performed with non-invasive imaging (e.g., optical coherence tomography, near infrared scanning laser ophthalmoscopes, including GDxPRO™ (Carl Zeiss Meditec), optical coherence tomography (OCT)-based pachymetry, including Visante omni (Carl Zeiss Meditec). In particular, OCT has come to be widely used for examining the retina. OCT has become prevalent in both anterior and posterior segment examination because of its resolution and imaging speed, which together allow accurate and real time 3D imaging of tissues under examination. Most currently available commercial posterior segment OCTs operate in the near infrared (NIR) region of the electromagnetic spectrum. Anterior segment OCTs and future posterior segment OCTs may operate in the range of about 1050 nm to about 1300 nm to allow for greater penetration into the ocular tissue. 
     Masks, such as those described in U.S. Patent Publication No. 2006/0265058, may be formed of any of a number of ocular compatible materials and biomaterials, including for example polyvinylidene fluoride (PVDF), and may be pigmented with, for example, titanium, gold, or carbon particles to provide opacity. However, such a mask is practically 100% opaque to both visible and NIR light. This application describes ocular devices and methods to incorporate NIR transmission in a mask for an intracorneal inlay, and/or an intraocular lens, or other ophthalmic device. The NIR transmissive material can be incorporated with any mask or intraocular lens embodiment discussed herein. The materials described hereinbelow may be used in lieu of or in conjunction with other visible light-blocking materials in a mask or may be used to form the mask itself, regardless of whether the mask is in the form of a corneal inlay or incorporated into an IOL. 
     In some embodiments disclosed herein, select bandpass dyes are incorporated into the gross material of the mask or intraocular lens. For example, an orange dye which absorbs only light in the range of about 400-520 nm will allow all other wavelengths to pass, i.e. less than about 400 nm or higher than about 520 nm. Therefore, it is the object of some embodiments to use one or more bandpass dyes with varying absorption spectra to selectively block only predetermined ranges of the electromagnetic radiation spectrum while selectively allowing the transmission of others. This design principle becomes particularly valuable when observing that the currently prevalent ocular imaging modalities of optical coherence tomography, near infrared scanning laser ophthalmoscopes, and optical coherence tomography-based pachymetry rely almost exclusively on NIR light in the range of 1050 to 1300 nm. Therefore, as is discussed below, it is possible to create a mask capable of blocking the transmission of substantially all visible light to provide the benefit of a mask while remaining transparent to the NIR light used in ocular imaging. 
     Any combination of one or more light absorbing dyes may be used to block a desired spectrum of electromagnetic radiation wavelengths. One method of blocking the visible spectrum of electromagnetic radiation is to take a three-prong approach and use a red dye (to block light from about 500-600 nm), a blue dye (to block light from about 600-700 nm), and a yellow dye (to block light from about 400-500 nm), thereby blocking substantially the entire spectrum of visible light. It is also possible to use bandpass dyes with broader absorption spectra and omit one or more dyes from the three-prong approach. For example, the inventors have found at least one dye composition which uses only an orange dye capable of absorbing (and thereby blocking) electromagnetic radiation in the range of about 400-540 nm and a blue-green dye capable of absorbing (and thereby blocking) electromagnetic radiation in the ranges of about 360-440 nm as well as about 540-700 nm, thereby obviating the need for a yellow dye. 
     Regarding the use of an orange or red dye to block electromagnetic radiation, any orange or red dye of the azo type or others capable of absorbing electromagnetic radiation may be used. Such an orange or red dye may absorb electromagnetic radiation in the range of about 350-600 nm, including the ranges of about 375-575 nm, about 400-550 nm, about 425-525 nm, and about 450-500 nm, or any other range of wavelengths selected to be used in a tailored composition of dyes to achieve a desired absorption profile. In some embodiments, the orange or red dye absorbs electromagnetic radiation in more than one range, i.e., has more than one lambda max. The red dye may include at least one methacrylate or acrylate moiety or other reactive moiety. Such acrylate or methacrylate or other moieties and possible subsequent covalent bonding, discourages, if not eliminates, a substantial amount of subsequent leaching or release of the dye molecule over time and through extended use. The incorporation of moieties, including but not limited to acrylate and methacrylate moieties, into the dye molecule allows a high degree of covalency and a concomitantly high degree of dye loading. This is particularly useful in ocular devices with particularly thin cross sections as high dye loadings are one technique in these applications to achieve appropriate opacity. At high dye loadings achieving high covalency up to and including 100% may be difficult. As covalency declines, dye bleeding into the surrounding matter can result. For example, dye bleeding into the clear/transparent regions of the IOL or other non-corneal ocular device or, if the device is implanted into the cornea, into the surrounding corneal tissues can occur if covalency is not sufficiently high. Such dye bleeding is highly undesirable in ocular devices. The methacrylated or acrylated dyes disclosed herein may achieve a high degree of covalent bonding sufficient for corneal inlays and other thin cross section ocular devices. These and other similar dyes will be substantially free of dye bleeding associated with insufficient covalency in a thin, high concentration dye structure. Alternatively, in some embodiments the orange dye may be reacted with a polymer after polymerization using reactive functional groups such as methacrylate or acrylate: the dye linker moiety may be grafted to the polymer after polymerization to achieve substantially the same result as discussed above. 
     In some embodiments, the orange dye used is Disperse Red 1 acrylate, 2-[N-ethyl-4-[(4-nitrophenyl)diazenyl]anilino]ethyl prop-2-enoate. The structure for Disperse Red 1 Acrylate is shown below: 
     
       
         
         
             
             
         
       
     
     Disperse Red 1 acrylate has a lambda max, or maximum absorbance, at about 480 nm. In other embodiments, any red or orange dye with similar or appropriate absorption spectra or range may be used. 
     The orange and red dyes mentioned in the immediately preceding paragraphs may be particularly useful for incorporation in hydrophobic ocular biomaterials, many of which are known in the art. Examples of well-known hydrophobic ocular biomaterials include hydrophobic acrylic, silicone elastomer, and PMMA. In an alternative embodiment, it is desirable to use hydrophilic ocular biomaterials, many of which are also known in the art. Examples of well-known hydrophilic ocular biomaterials include hydrophilic acrylic, collagen, silicone hydrogels, and polyvinylpyrrolidone. In such embodiments, it may be desirable to use ionic dyes capable of blocking substantially all of the visible spectrum of electromagnetic radiation while allowing transmission of substantially all of the NIR spectrum of electromagnetic radiation (i.e., a red ionic dye, a blue ionic dye, and a yellow ionic dye to therefore block substantially the entire spectrum of visible electromagnetic radiation). 
     Regarding the use of a blue-green dye to block electromagnetic radiation, any blue-green dye may be used which is capable of absorbing electromagnetic radiation in the range of about 550-700 nm, including the ranges of about 575-675 nm, about 600-650 nm, or any other range of wavelengths selected to be used in a tailored composition of dyes to achieve a desired absorption profile. In some embodiments, the blue-green dye absorbs electromagnetic radiation in more than one range, i.e., has more than one lambda max. 
     In some embodiments, the blue-green dye used is the dimethacrylate derivative of 1,4-Bis(4-ethylanilino) anthraquinone (a close relative of Solvent Green 3, i.e. 1,4-Bis(4-methylanilino)anthraquinone), formally known as 2-[4-({4-[(4-{2-[(2-methylprop-2-enoyl)oxy]ethyl}phenyl)amino]-9,10-dioxo-9,10-dihydro-anthracen-1-yl}amino)phenyl]ethyl-2-methyl prop-2-enoate. The structure of dimethacrylate deriviative of 1,4-Bis(4-ethylanilino) anthraquinone is shown below: 
     
       
         
         
             
             
         
       
     
     The dimethacrylate of 1,4,-Bis(4-ethylanilino)anthraquinone has lambda max, or maximal absorbance, in the visible spectral range at about 624-644 nm, about 591-611 nm, and about 394-414 nm. Dimethacrylate of 1,4,-Bis(4-ethylanilino)anthraquinone has an additional benefit in creating masks as disclosed in this application because it is bifunctional in that it has two methacrylate functional groups. Because of these two functional groups, the blue-green dye molecule is very efficiently covalently incorporated into a polymeric base material. The incorporation of moieties, including but not limited to acrylate and methacrylate moieties, into the dye molecule allows a high degree of covalency and a concomitantly high degree of dye loading. This is particularly useful in ocular devices with particularly thin cross sections as high dye loadings are one technique in these applications to achieve appropriate opacity. At high dye loadings achieving high covalency up to and including 100% may be difficult. As covalency declines, dye bleeding into the surrounding matter can result. For example, dye bleeding into the clear/transparent regions of the IOL or other non-corneal ocular device or, if the device is implanted into the cornea, into the surrounding corneal tissues can occur if covalency is not sufficiently high. Such dye bleeding is highly undesirable in ocular devices. The methacrylated or acrylated dyes disclosed herein may achieve a high degree of covalent bonding sufficient for corneal inlays and other thin cross section ocular devices. These and other similar dyes will be substantially free of dye bleeding associated with insufficient covalency in a thin, high concentration dye structure. Alternatively, in some embodiments the blue-green dye may be reacted with a polymer after polymerization using reactive functional groups such as methacrylate or acrylate: the dye linker moiety may be grafted to the polymer after polymerization to achieve substantially the same result as discussed above. When grafting the dye linker moiety to the polymer after polymerization, i.e., surface bonding the dye, it may be useful to diffuse dye into the polymer matrix to achieve more complete incorporation and therefore a higher degree of opacity and electromagnetic radiation absorption. Additionally, the molecule&#39;s bifunctionality dramatically reduces the required concentration of crosslinking molecule (such as ethylene glycol dimethacrylate) in the final formulation. Below is shown the general structure of a monomeric 1,4,-Bis(alkylarylamino)anthraquinone dye: 
     
       
         
         
             
             
         
       
     
     The properties and synthesis of the dimethylacrylate of 1,4,-Bis(4-ethylanilino)anthraquinone are generally described in U.S. Pat. No. 5,055,602, which is incorporated by reference herein in its entirety. In the aforementioned molecule, “R” represents, most generally, an aryl, alkyl or arylalkyl linker with 2 to 12 carbon atoms and “X” represents, most generally, any polymerizable, unsaturated organic functional group (such as a methacrylate, acrylate, vinyl carbonyl, or vinyl carbamate functional moieties). Variations of this molecule in which “R” is an arylalkyl linker may be particularly useful in applications such as those disclosed herein. In some embodiments, the aryl of the arylalkyl linker may be a single aromatic ring. In other embodiments, the aryl group may consist of more than one separate aromatic ring or alternatively it may be one or more fused multiple aromatic ring systems. Additionally, in some embodiments the aryl linker may be bonded directly to the nitrogen of the mother molecule (shown above) as shown below. In other embodiments, the aryl linker, as just disclosed, may be situated between two separate alkyl groups where the proximate alkyl group bonds to the nitrogen of the mother molecule and the distal alkyl group bonds to the carbon of the methacrylate or acrylate via the distal alkyl group&#39;s reactive end group. The alkyl group, whether it be only one alkyl group on the distal side of the aryl group or two alkyl groups, one on each of the proximate and distal sides of the aryl group, may be any alkyl group, in linear, branched or ring form, in the range of about 1-15 carbon atoms, including the ranges of about 1-12 carbon atoms, about 1-10 carbon atoms, about 1-8 carbon atoms, about 1-6 carbon atoms, about 1-4 carbon atoms, and about 1-2 carbon atoms, including also only one carbon atom alkyl groups (methylene groups), or any alkyl group or groups which serves to link the mother molecule, through the aryl group, to the methacrylate or acrylate group (on each side of the bilaterally symmetrical mother molecule). In some embodiments the alkyl group distal to the aryl group includes an organic functional moiety that may facilitate bonding to the final distal X group (as mentioned above, in some cases the X group is a methacrylate or acrylate functional group). In some embodiments, additional moieties may be included in the alkyl linkers, for example: oxygen heteroatoms, nitrogen heteroatoms, or sulfur heteroatoms. The addition of such heteroatoms may facilitate other chemistries or impart the added benefit aiding in the control of solubility. 
     To create the dimethacrylate of 1,4,-Bis(4-ethylanilino)anthraquinone, the R groups are phenyl alkyl linkers and the X groups are methacryl groups, as shown below: 
     
       
         
         
             
             
         
       
     
     In other embodiments, any green dye with appropriate absorption spectra may be used. More specifically to the aforementioned molecule, the linker (the “R Group” shown above) may be modified while retaining substantially all of the desired absorbance properties of the dye. Some examples of the broad class of phenyl alkyl radicals are listed above. These examples are not intended to limit this disclosure, rather they are illustrative examples of only a few possible linkers. As mentioned above, additional moieties may be included in the alkyl linkers, for example: oxygen heteroatoms, nitrogen heteroatoms, or sulfur heteroatoms. Additionally, the use of acryl groups instead of methacryl groups (the “X Group” shown above) should have little to no impact on the absorbance properties of the dye molecule. Lastly, a vinyl substituent in place of the acryl or methacryl double bond would efficiently add to the polymer chain via free radical mechanism. There are many additional possible modifications which would not adversely affect the desirable properties of the dye molecules disclosed herein and may therefore be applicable to and used in NIR transmissible masks as disclosed herein. The aforementioned alterations to the dimethacrylate of 1,4,-Bis(4-ethylanilino) are not intended to limit the scope of this application, rather it is understood that such alterations are merely representative of select classes of possible changes that can be made to the molecule without substantial adverse effects on its absorbance properties as would be recognized by those skilled in the art. 
     In other embodiments, any dye in the classes of dyes known as azo (including monoazo and bisazo) and anthraquinone which when used alone or in concert with other dyes (of its own class or any other class) meets the visible absorption requirements of absorbing substantially the entire visible spectrum of electromagnetic radiation may be used. 
     An example of the synthesis of the dimethacrylate of 1,4,-Bis(4-ethylanilino)anthraquinone is presented below. The percentages given below and elsewhere herein for formulations are by weight unless stated otherwise. 
     Example 1: Synthesis of the Dimethacrylate of 1,4,-Bis(4-Ethylanilino)Anthraquinone 
     The dimethacrylate of 1,4,-Bis(4-ethylanilino)anthraquinone: synthetic mixture consisted of 
     
       
         
           
               
               
               
               
               
             
               
                   
               
             
            
               
                   
                   
                 Intermediate 
                  5.2% 
                   
               
               
                   
                   
                 Leucoquinizarin 
                 23.3% 
               
               
                   
                   
                 2-(4-Aminophenyl) Ethanol 
                 76.7% 
               
               
                   
                   
                 Ethylene Glycol 
                 excess (to dissolve) 
               
               
                 Intermediate ingredients 
                  {open oversize brace}  
                 Acetone 
                 excess 
                  {close oversize brace}  
               
               
                   
                   
                 Deionized Water 
                 excess 
               
               
                   
                   
                 0.625M NaOH 
                 excess 
               
               
                   
                   
                 Dry Acetonitrile 
                 78.9% 
               
               
                   
                   
                 Triethanolamine 
                 10.4% 
               
               
                   
                   
                 Methacryloyl Chloride 
                  5.5% 
               
               
                   
                   
                 Ethylene Glycol 
                 excess (to dissolve) 
               
               
                   
               
            
           
         
       
     
     The dimethacrylate of 1,4,-bis(4-ethylanilino)anthraquinone (or 2-[4-({4-[(4-{2-[(2-methylprop-2-enoyl)oxy]ethyl}phenyl)amino]-9,10-dioxo-9,10-dihydro-anthracen-1-yl}amino)phenyl]ethyl-2-methyl prop-2-enoate) was synthesized in the following manner. 10 grams of leucoquinizarin and 33 grams of aminophenyl ethanol were stirred under a nitrogen blanket in an oil bath for five hours at 150° C. The chemical mixture was then cooled to 100° C. at which point dry ethylene glycol was added to dissolve the solid and the nitrogen blanket was removed. Air was then bubbled into the mixture and everything was incubated for 6 to 8 hours at 100° C. After incubation, the mixture was dissolved in acetone and filtered. The filtrate was recovered and 0.625M NaOH was added drop-wise to the filtrate resulting in formation of needle-like blue-green precipitate. The precipitate was recovered with filtration and washed with deionized water and dried under vacuum. To each gram of intermediate, 15 grams of dry acetonitrile and 2 grams of triethanolamine were added to dissolve the mixture. 1 mL of methacryloyl chloride was added dropwise to the mixture with continuous stirring. After mixing for 3 hours at room temperature, ethylene glycol was added to dissolve the crude product. Deionized water was added to the crude product liquor to selectively precipitate the product dimethacrylate of 1,4,-Bis(4-ethylanilino)anthraquinone. After recovering the product with filtration, the product was purified by crystallization from an acetone water mixture. Crystals were collected by filtration and vacuum dried for 6 to 8 hours. The result was the final highly purified product, 2-[4-({4-[(4-{2-[(2-methylprop-2-enoyl)oxy]ethyl}phenyl)amino]-9,10-dioxo-9,10-dihydro-anthracen-1-yl}amino)phenyl]ethyl-2-methyl prop-2-enoate (purity&gt;95% by HPLC). 
     For the following, all percentages refer to weight percent. To create the intermediate, in some embodiments some parameters may be altered. For example, the 2-(4-aminophenyl)ethanol/leucoquinizarin ratio (by weight) may be used in the range of about 1.1%-5.7%, including the ranges of about 2.1%-4.7%, about 3.1%-3.6% and about 3.3%, or any other concentration of aminophenyl ethanol which allows proper synthesis of the intermediate. In some embodiments the leucoquinizarin and aminophenyl ethanol are mixed under nitrogen blanket. In other embodiments those chemicals may be mixed under any inert or non-reactive gas blanket, including for example helium, neon, argon, krypton, and xenon. In some embodiments the chemical mixture may be cooled to a temperature anywhere in the range of about 70° C.-140° C., including the range of about 95° C.-105° C., and about 100° C. In some embodiments, the gas bubbled into the mixture may be any mixture of oxygen with inert noble gases (helium, neon, argon, krypton, and xenon) or nitrogen. In some yet other embodiments, the deduced intermediate may be oxidized through chemical oxidation: for example by using ozone or hydrogen peroxide. In some embodiments, the NaOH solution may be used in a molarity range of about 0.5-0.7 molar, including the ranges of about 0.54-0.66 molar, about 0.58-0.62 molar, and including about 0.6 molar. 
     Once the intermediate has been created, certain other parameters may be altered. For example, the intermediate may be used in the range of about 2-12% including the ranges of about 3%-10%, about 4%-8%, about 5%-7% and including about 5.2%. In some embodiments, the dry acetonitrile may be used in the range of about 60%-90%, including the ranges of about 47%-57%, about 50%-54%, and about 78%. Other solvents, specifically those that are non-protic water soluble organic solvents, may be substituted for acetonitrile, including but not limited to: tetrahydrofuran, dimethysulfoxide, and dimethylformamide. Triethanolamine may be used in the range of about 10%-20%, including the range of about 10%-15%, and about 11.5%. Methacryloyl chloride may be used in the range of about 2.5%-8%, including the ranges of about 2.7%-7.5%, about 2.9%-7%, about 2.7%-6.5%, and about 5.5%-5.6%. Other glycols may be substituted for ethylene glycol, such as those liquid polyethylene glycols with a molecular weight less than 400 g/mol, including but not limited to: triethyleneglycol, tetraethylene glycol and pentaethylene glycol. Low molecular weight water miscible alcohols may also be substituted for ethylene glycol, including but not limited to N-butoxyethanol and ethylcellosolve. The time parameters given, including stirring times, drying times, and resting times may be altered to any times which allow the proper chemical or physical reactions to occur. 
     The blue-green dyes mentioned in the immediately preceding paragraphs may be particularly useful for incorporation in hydrophobic ocular biomaterials, many of which are known in the art. In an alternative embodiment, using hydrophilic ocular biomaterials, it may be desirable to use ionic dyes (of any color) capable of blocking substantially the entire visible spectrum of electromagnetic radiation while allowing transmission of substantially the entire NIR spectrum of electromagnetic radiation (i.e., a red ionic dye, a blue ionic dye, and a yellow ionic dye to therefore block substantially the entire spectrum of visible electromagnetic radiation). 
     Regarding the use of a yellow dye to block electromagnetic radiation, any yellow dye may be used which is capable of absorbing electromagnetic radiation in the range of about 350-450 nm, including the ranges of about 355-445 nm, about 360-440 nm, about 365-435 nm, about 370-430 nm, about 375-425 nm, about 380-420 nm, and about 385-415 nm, or any other range of wavelengths selected to be used in a tailored composition of dyes to achieve a desired absorption profile. In some embodiments, the yellow dye absorbs electromagnetic radiation in more than one range, i.e., has more than one lambda max. The yellow dye may include at least one methacrylate or acrylate moiety or other reactive moiety. Such acrylate or methacrylate or other moieties and subsequent covalent bonding, discourages, if not eliminates, a substantial amount of subsequent leaching or release of the dye molecule over time and through extended use. The incorporation of moieties, including but not limited to acrylate and methacrylate moieties, into the dye molecule allows a high degree of covalency and a concomitantly high degree of dye loading. This is particularly useful in ocular devices with particularly thin cross sections as high dye loadings are one technique in these applications to achieve appropriate opacity. At high dye loadings achieving high covalency up to and including 100% may be difficult. As covalency declines, dye bleeding into the surrounding matter can result. For example, dye bleeding into the clear/transparent regions of the IOL or other non-corneal ocular device or, if the device is implanted into the cornea, into the surrounding corneal tissues can occur if covalency is not sufficiently high. Such dye bleeding is highly undesirable in ocular devices. The methacrylated or acrylated dyes disclosed herein may achieve a high degree of covalent bonding sufficient for corneal inlays and other thin cross section ocular devices. These and other similar dyes will be substantially free of dye bleeding associated with insufficient covalency in a thin, high concentration dye structure. Alternatively, the yellow dye may be reacted with a polymer after polymerization using reactive functional groups such as methacrylate or acrylate: the dye linker moiety may be grafted to the polymer after polymerization to achieve substantially the same result as discussed above. 
     The yellow dyes mentioned in the immediately preceding paragraphs may be particularly useful for incorporation in hydrophobic ocular biomaterials, many of which are known in the art. In an alternative embodiment, using hydrophilic ocular biomaterials, it may be desirable to use ionic dyes (of any color) capable of blocking substantially the entire visible spectrum of electromagnetic radiation while allowing transmission of substantially the entire NIR spectrum of electromagnetic radiation (i.e., a red ionic dye, a blue ionic dye, and a yellow ionic dye to therefore block substantially the entire spectrum of visible electromagnetic radiation). 
     Regarding incorporation of the aforementioned dyes into a polymeric material, the inventors have found that when using a dye having reactive groups such as an acrylated or methacrylated dye, an effective mode of incorporation into the final product is to solubilize the dye in monomer prior to polymerization. The dyes may also be incorporated into the polymeric material post-polymerization by simply grafting the dye moiety onto the polymer itself after the homopolymer or copolymer has been created. 
     It may also be advantageous to incorporate an ultraviolet (UV) absorber into the mask material, along with the bandpass dyes that absorb the visible electromagnetic radiation. Such a UV absorber absorbs UV electromagnetic radiation with wavelengths smaller than about 400 nm. Including such a UV absorber protects the other bandpass dyes (such as disperse red 1 acrylate and dimethacrylate of 1,4,-Bis(4-ethylanilino)anthraquinone) preventing UV-induced photobleaching of dye molecules. For example, the protective function provided by UV absorber can be beneficial for the dimethacrylate of 1,4,-bis(4-ethylanilino)anthraquinone because this dye displays considerable absorbance in the range of about 250-300 nm and may therefore be particularly prone to UV induced photobleaching. 
     In embodiments including UV absorber, the UV absorber may be any UV absorber, or combination of two or more UV absorbers. The UV absorber may include a benzotriazole UV Absorber, such as ([2-(5-chloro-2H-benzotriazole-2-yl)-6-(1,1-dimethylethyl)-4-ethenylphenol, and/or it may include any compound or combination of two or more compounds capable of absorbing electromagnetic radiation in the UV range. 
     Some embodiments of the mask disclosed herein use both, and only, Disperse Red 1 acrylate (as an orange dye) and dimethacrylate of 1,4,-bis(4-ethylanilino)anthraquinone (as a blue-green dye) in concert with a UV absorber. In this mixture, the disperse red 1 acrylate absorbs in the range of about 390-550 nm, the dimethacrylate of 1,4,-bis(4-ethylanilino)anthraquinone absorbs in the range of about 360-440 &amp; about 520-700 nm, and the UV absorbs in the range of less than about 400 nm (thereby yielding the aforementioned protective benefit). Because such effective blue-green and orange dyes are used, a yellow dye is rendered unnecessary in this formulation and therefore does not need to be included, although it may be included if desired. Provided suitable concentrations of the aforementioned dyes and absorbers are used, substantially the entire visible electromagnetic radiation spectrum is substantially absorbed or blocked. 
     Example 2: Synthesis of NIR Transparent Mask Material 
     The NIR transparent mask material formulation consisted of: 
     
       
         
           
               
               
             
               
                   
               
             
            
               
                 Butyl Acrylate 
                 51.60% 
               
               
                 Ethylmethacrylate 
                 45.07% 
               
               
                 Benzotriazole UV Absorber 
                 0.50% 
               
               
                 Ethyleneglycoldimethacrylate 
                 0.50% 
               
               
                 Azobisisobutyronitrile 
                 0.13% 
               
               
                 Disperse Red 1 Acrylate 
                 0.20% 
               
               
                 Dimethacrylate of 1,4,-Bis(4-ethylanilino)anthraquinone 
                 2.00% 
               
               
                   
               
            
           
         
       
     
     The following synthesis procedure is directed toward a particular material. However, one skilled in the art may readily adapt this procedure for use with other monomers, UV absorbers, dyes, and the like. The NIR transparent mask material was synthesized in the following manner. For clarity&#39;s sake, the percentages referred to herein relate to the weight percent of the total material weight. First the following dye solutions were created: disperse red 1 acrylate (2[N-ethyl-4-[(4-nitrophenyl)diazenyl]anilino]ethyl prop-2-enoate) in butyl acrylate and dimethacrylate of 1,4,-bis(4-ethylanilino)anthraquinone (2-[4-({4-[(4-{2-[(2-methylprop-2-enoyl)oxy]ethyl}phenyl)amino]-9,10-dioxo-9,10-dihydro-anthracen-1-yl}amino)phenyl]ethyl-2-methyl prop-2-enoate in ethylmethacrylate. To create the disperse red 1 acrylate dye and butyl acrylate solution, 0.2% disperse red 1 acrylate was added to 51.60% butyl acrylate. To create the dimethacrylate of 1,4,-bis(4-ethylanilino)dye and ethylmethacrylate solution, 2.00% dimethacrylate of 1,4,-bis(4-ethylanilino)anthraquinone was added to 45.07% ethylmethacrylate. The dye solutions were then sonicated well until the dyes had fully dissolved in their respective solutions and then were set aside. 0.13% azobisisobutyronitrile and 0.5% benzotriazole UV absorber were weighed into a flask and the following was then added: 51.60% butyl acrylate/0.2% disperse red 1 acrylate dye solution (made previously), 45.07% ethylmethacrylate/2.00% dimethacrylate of 1,4,-bis(4-ethylanilino) solution (made previously), and 0.5% ethyleneglycoldimethylacrlylate. The mixture was purged with nitrogen and stirred for one hour without heat. To cure, glass molds were filled with the material. The molds were transferred to an oven and the mixture cured using the following time and temperature parameters: ramp 10 minutes to 65° C., hold 12 hours at 65° C., ramp 1 hour to 110° C., hold 4 hours at 110° C., ramp 2 hours to 30° C. 
     To create the NIR transparent mask material, some parameters may be altered. For example, disperse red 1 acrylate may be used in the range of about 0.1%-1.0%, including the ranges of about 0.12%-0.8%, about 0.14%-0.6%, about 0.16%-0.4%, and about 0.18%-0.3%, including about 0.2%, or any other concentration of disperse red 1 acrylate which provides a desired absorption profile. Dimethacrylate of 1,4,-bis(4-ethylanilino)anthraquinone may be used in the range of about 1.0%-3.0%, including the ranges of about 1.2%-2.8%, about 1.4%-2.6%, about 1.6%-2.4%, and about 1.8%-2.2%, including about 2.0%, or any other concentration of dimethacrylate of 1,4,-Bis(4-ethylanilino)anthraquinone which provides a desired absorption profile. Butyl acrylate, to which the disperse red 1 acrylate dye is added, may be used in the range of about 30%-70%, including the ranges of about 35%-65%, about 40%-60%, and about 45%-55%, including about 50%, or any other concentration of butyl acrylate which allows the formation of the NIR transparent mask material. Ethylmethacrylate, to which the dimethacrylate of 1,4,-bis(4-ethylanilino)anthraquinone is added, may be used in the range of about 25%-65%, including the ranges of about 30%-60%, about 35%-55%, about 40%-50%, and about 42%-46%, including about 44%, or any other concentration of ethylmethacrylate which allows the formation of the NIR transparent mask material. Azobisisobutyronitrile may be used in the range of about 0.05%-0.5%, including the ranges of about 0.07%-0.40%, about 0.9%-0.30%, and about 0.11%-0.20%, including about 0.13%, or any other concentration of azobisisobutyronitrile which allows the formation of the NIR transparent mask material. Ethyleneglycoldimethacrylate may be used in the range of about 0.025%-10.0%, including the ranges of about 0.075%-9.0%, about 0.125%-8.0%, about 0.175%-7.0%, about 0.225%-6.0%, about 0.275%-5.0%, about 0.325%-4.0%, about 0.375%-3.0%, about 0.425%-2.0%, about 0.475%-1.0%, including about 0.5%, or any other concentration of ethyleneglycoldimethacrylate which allows the formation of the NIR transparent mask material. Benzotriazole UV absorber may be used in the range of about 0.0%-2.5%, including the ranges of about 0.0%-2.0%, about 0.0%-1.5%, and about 0.0%-1.0%, including about 0.5%, or any other concentration of benzotriazole UV absorber which allows the formation of the NIR transparent mask material. In addition to varying the amounts, other dyes, solvents, UV absorbers, monomers, polymers and the like may be substituted as desired to make materials suitable for use as a mask. 
     When all the aforementioned chemicals are mixed together, the mixture may be placed under a nitrogen stream or any inert or generally unreactive gas stream, including for example helium, neon, argon, krypton, and xenon. 
     The time parameters given, including stirring times, heating times, and resting times may be altered to any times which allow the proper chemical and/or physical reaction to occur. Furthermore, the temperature parameters may be altered to any temperatures which allow the proper chemical and/or physical reactions to occur. The disclosed times and temperatures are intended to be representative of only one possibility among many and are understood not to limit the scope of this disclosure. 
     The dyes disclosed herein may be used in concert with any polymer determined to be appropriate for ocular uses by one of ordinary skill in the art. Any concentration of any number of varied colored absorbing dyes (including orange, yellow and green and any other such absorbing dyes) may be used with or without a UV absorber. As the dyes are functionalized with acryl or methacryl or other suitable moieties, they may be reacted with any number of polymer units prior to or after polymerization in any concentration possible and desired. 
     Using the aforementioned bandpass dyes and UV absorber, it is clear that the embodiments disclosed herein envision tailorability, through bandpass dye choice and concentration, of the electromagnetic radiation allowed to pass through the mask. For example, the ocular device may comprise one or more materials which obstruct the majority of visible light wavelengths up to about 750 nm and transmit in the range of about 750 nm to about 1300 nm. Similarly, the ocular device may transmit up to a wavelength of about 1500 nm or the ocular device may transmit in the range of about 1050 nm to about 1300 nm. Allowing transmission in these ranges will make the inlay and/or IOL mask effectively invisible to a diagnostic OCT light source. By way of example, a material that uses the orange dye, disperse red 1 acrylate, and the blue-green dye, dimethacrylate of 1,4,-Bis(4-ethylanilino)anthraquinone, and the benzotriazole UV Absorber has been observed to block about 99% of all visible electromagnetic radiation in the range of about 400 to about 700 nm, while allowing substantially all Near Infrared (NIR) electromagnetic radiation, greater than about 700 nm, to pass through the mask.  FIG. 67  shows a transmission spectrum of a 200 micron thick hydrophobic acrylic mask produced by the inventors using the methods and materials disclosed herein. As can be seen, the inventors succeeded in blocking substantially the entire visible spectrum of electromagnetic radiation while allowing the transmission of substantially the entire NIR spectrum of electromagnetic radiation. 
     Intraocular lenses may be implanted in older patients who are more likely to have concurrent retinal complications. Unlike a corneal inlay which may be easily removed, the IOL removal procedure is non-trivial. Therefore, it is particularly important that any mask included in or on an IOL not impede imaging of the eye using NIR techniques. 
     Although certain inlays with a small-aperture mask may not impede retinal examination with OCT (see, e.g., Casas-Llera et al, “Retinal imaging after corneal inlay implantation,” Journal of Cataract &amp; Refractive Surgery, Vol. 37, Issue 9, September 2011, pages 1729-1731, the entirety of which is hereby incorporated by reference), some practitioners could still consider the mask to be obstructive to retinal examination especially given that minimum pupil size provided by OCT manufacturers is ≥2 mm. Furthermore, an IOL with a small-aperture mask may not similarly allow OCT examination. Use of a mask with materials that are more amenable to retinal examination, such as those mentioned above, could provide improved usability and market acceptability. Use of such materials in corneal inlays and IOLs may aid in improved retinal examination with OCT. 
     In some applications, the masks are formed of a material substantially opaque to visible light while being selectively transparent to certain other wavelengths of electromagnetic radiation. The substantially opaque material can be used in connection with any of the masks described herein. The mask can also include any of the features described above. 
     For example, an ocular device includes a material that obstructs visible light up to 750 nm and transmits in the range of 750 to 1500 nm. Allowing transmission in these ranges will make the inlay and an IOL mask invisible to the diagnostic OCT light source. Such an ocular device would be invisible to the electromagnetic spectrum used by diagnostic devices. This would aid clinicians in examining the ocular tissues in both anterior and posterior segments of the eye. 
     The ocular device can comprise one or more polymeric compounds that would have substantially 100% transmission in the spectral ranges of about 750 nm to about 1500 nm (NIR) while being substantially opaque in visible ranges. For example, vinyl-functional dyes of yellow, red, and green, each with band pass transmission in selective regions of the visible spectrum, can be blended into a mixture of monomers that form the polymer matrix. The mixture can include a cross-linking molecule and a thermal initiator. The mixture can be introduced into a pocket in a base polymer blank and cured in-situ to form the mask and the lens can be machined from this blank with the mask. In another example, non-functional dyes with band pass transmission in selected regions of the visible spectrum such as disperse yellow, disperse red, and solvent green 3 can be mixed in with PVDF and DMAC solvent which can then be spun-cast. Other example uses are described in Patel C K, Yusuf I H and Menezo V, “Imaging the macula through a black occlusive intraocular lens,” Arch Ophthalmol 2010, 128: 1374-1376 and Yusuf I H, Peirson S H and Patel C K, “Occlusive IOLs for intractable diplopia demonstrate a novel near-Infrared window of transmission for SLO/OCT imaging and clinical assessment,” IOVS, 2011, 52: 3737-3743, the entirety of each of which is hereby incorporated by reference. To the naked eye and to standard clinical examination, the mask would appear opaque and similar to certain conventional masks that are opaque to both visible and NIR spectral ranges. However, the mask would be invisible when viewed with a NIR light source (e.g., the mask would permit transmission of NIR). 
     Various embodiments have been described above. Although the invention has been described with reference to these specific embodiments, the descriptions are intended to be illustrative and are not intended to be limiting. Various modifications and applications may occur to those skilled in the art without departing from the true spirit and scope of the invention as defined in the appended claims.