Abstract:
The present invention is directed to a method of manufacturing spectacle lens eyewear using a block mold, front and back optical inserts, front and back optical insert gaskets, a protractor insert, a closing mechanism and a preformed frame, the method comprising the steps of: selecting a front optical insert from a look up table or computer program product and assembling the insert into the block mold; selecting a front optical insert gasket and assembling the gasket onto the front optical insert; assembling the frame front onto the front optical insert gasket; selecting a back optical insert gasket and assembling the gasket onto the back side of the frame front; selecting a back optical insert from a look up table or computer program product and assembling the insert onto the back optical insert gasket; assembling the protractor insert and adjusting the position of the back optical insert to the axis indicated on a look up table or computer program product; assembling the mold closing mechanism and securing the mold; filling the cavity through a first capillary tube; curing the closed mold to polymerize the lenses; removing the ophthalmic eyewear from the block mold and releasing the front and back optical inserts and insert gaskets; and removing the capillary tube housing and attaching earpieces.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally ophthalmic eyewear. More particularly, the present invention relates to ophthalmic eyewear with prescription lenses for the correction of low and higher order aberrations and presbyopia comprising lenses that are cast into a frame or simultaneously with the casting of the frame, and methods and apparatus of the casting system. 
     BACKGROUND OF THE INVENTION 
     Conventional spectacle eyewear has been produced by the process of first manufacturing frames or frame components followed by cutting and edging lenses to fit the frame, or to be mounted together by a bridge and including end-pieces to which temples or earpieces are attached. The spectacle lenses are produced in an uncut form by way of casting or molding a semi-finished blank with one surface complete and surfacing the opposing surface to create a finished prescription or by casting or molding a lens wherein both surfaces are finished. 
     The finished uncut blank is then oriented and displaced to produce a final astigmatism axis and centering of the lens to correspond with the intended vertical and horizontal size of the frame and the pupillary distance of the intended wearer. The conventional methods of fabricating eyewear require machinery for cutting and edging finished blanks to a proper size and shape of eyewear. 
     It is estimated that more than 300 million people in the world are functionally blind due to uncorrected refractive errors. The majority of these people lack the geographic or economic access to eye examinations and acquisition of prescription eyewear. The required inventory of uncut semi-finished blanks, finished blanks, surfacing equipment and cutting and edging equipment is far too costly and skilled-labor intensive to be available to this population in need of prescription eyewear. Even if the equipment and labor were available, the power and service requirements for the machinery remain high and the need for inventory of semi-finished or finished blanks persists. 
     Charitable organizations are known to conduct missions to provide eye examination services and eyewear to this population. The most common practice is to collect used eye glasses, catalog the prescriptions and attempt to match a required prescription with one found in the collected used eye glasses. The practice of collection, cataloging, transporting and delivering the used eyewear is inherently inefficient and the result is most often a poorly matched prescription in a used and questionably serviceable frame. 
     SUMMARY OF THE INVENTION 
     Various embodiments of the present invention are directed to ophthalmic eyewear with prescription lenses for the correction of low and higher order aberrations and presbyopia such as lenses that are cast into a frame or simultaneously with the casting of the frame, and methods and apparatus of the casting system. 
     The low cost eyewear described herein does not require machinery or skilled labor for manufacturing and can be produced in the field with minimal or no electrical power. Some embodiments of the present invention describe eyewear produced from a liquid monomer that is cured with near ultraviolet and white light and/or sunlight along with a frame of the same material, or into a preformed frame or by encapsulation of components of rimless frame components. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A and 1B  are side and perspective views, respectively, of ophthalmic spectacle lens eyewear in accordance with one embodiment of the present invention. 
         FIG. 1C  is a perspective view of a gasket for use in the ophthalmic spectacle lens eyewear of  FIGS. 1A and 1B . 
         FIG. 2A  is a perspective view of a block mold for the ophthalmic spectacle lens eyewear of  FIGS. 1A and 1B , in accordance with one embodiment of the invention. 
         FIGS. 2B and 2C  are side view of the block mold of  FIG. 2A . 
         FIG. 2D  is a top view of the block mold of  FIG. 2A . 
         FIGS. 3A and 3B  are side views of a one-piece block mold for the ophthalmic spectacle lens eyewear of  FIGS. 1A and 1B , in accordance with one embodiment of the invention. 
         FIGS. 3C-3E  are top, top perspective, and bottom perspective views, respectively, of the one-piece block mold of  FIGS. 3A and 3B . 
         FIGS. 4A-4D  are perspective, front, side, and top views, respectively, of an alternate frame in the form of a three piece mount, in accordance with one embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     In the following paragraphs, the present invention will be described in detail by way of example with reference to the attached drawings. Throughout this description, the preferred embodiment and examples shown should be considered as exemplars, rather than as limitations on the present invention. As used herein, the “present invention” refers to any one of the embodiments of the invention described herein, and any equivalents. Furthermore, reference to various feature(s) of the “present invention” throughout this document does not mean that all claimed embodiments or methods must include the referenced feature(s). 
     The present invention relates to ophthalmic eyewear with prescription lenses for the correction of low and higher order aberrations and presbyopia. In some embodiments, the lenses that are cast into a frame or simultaneously with the casting of the frame. Methods for casting the lenses into a frame are also provided. 
     Various embodiments of the invention are directed to spectacle lens ophthalmic eyewear including a frame front with a bridge or nosepiece and end-pieces for attaching earpieces, and at least one of a right and left lens that is cast into the frame or around the mounts for the nose-piece and the end-pieces, or simultaneously with the frame front. A block mold is provided along with a front and back optical insert, a front gasket and a back gasket, a protractor insert for alignment of the axis of at least one of the front and back inserts, and a means of closing and applying force to cause the mold, optical inserts and gaskets to seal. A curing station or means of directing ambient sunlight may be provided. Alternatively, the curing or polymerizing in situ on the eyeglass frame or any other frame can be achieved by the controlled application of heat. 
     A. Ophthalmic Eyewear of the Present Invention 
     Referring now to the figures, which are illustrative of multiple embodiments of the present invention only and are not for purposes of limiting the same,  FIGS. 1A and 1B  depict ophthalmic spectacle lens eyewear in accordance with one embodiment of the present invention. The ophthalmic eyewear  100  includes frame front  101  with a bridge or nose piece  102  and end-pieces  103  to which conventional temples or earpieces are attached. The frame also includes a pair of eyewire portions  104  for holding lenses  107 . A housing  106  including two capillary tubes  105  is attached to each eyewire portion  104  such that the capillary tubes  105  are in fluid communication with the interior side of the eyewire portion  104 . 
     During formation of the lenses, a monomer blend containing initiators and/or catalysts is directed into a lens cavity through one capillary tube  105  in the capillary housing  106  in a manner that allows the air to release through the alternate capillary tube  105  in the same capillary housing  106 . The capillary tubes  105  are capable of retaining a volume in excess of the shrinkage that occurs during the monomer blend polymerization. In addition, the capillary tubes  105  prevent the formation of an air bubble in the lens  107  by retracting liquid monomer into the prescription lens as required. In further embodiments, a chamber other than a capillary tube may be provided to retain an additional about 2-5% of the volume of the lens  107 . The capillary tube housings  106  are removed after the lenses  107  are cast into the frame front  101 . 
     With further reference to  FIGS. 1A and 1B , the frame front  101  includes a channel  108  to assist in retaining the cast lenses  107  in the frame front  101  and a notch or extrusion  109  in the channel to prevent the lenses  107  from rotating in the event the shape of the eyewire portion  104  is round. In some embodiments, the anterior and posterior aspect of the eyewire portion  104  is flat to accommodate a flat gasket  110  ( FIG. 1C ). The gasket  110  may be selected from a plurality of gaskets having different thicknesses that compensate for both severe and minor prescriptions having a variety of center and edge thicknesses. In further embodiments, the frame front  101  is rounded and an inverse curved surface gasket is employed. The gasket  110  and frame front  101  have a similar surface shape to produce a proper seal. In the illustrated embodiment, a curved channel  108  is employed in the eyewire portions  104  of the frame front  101 . The curved shape acts to improve exposure to light and achieve more complete curing as compared to a conventional V-shaped channel that may shadow and cause resultant incomplete polymerization. In an alternative implementation, a V-shaped channel may be employed. In one implementation, the mold housing for forming ophthalmic eyewear  100  may be made of acrylic, which transmits most of the UV light. In other implementations, the mold may be made of any hard clear material that will transmit the majority of the UV light, such as polycarbonate. The ring-shaped gaskets of  FIGS. 1 and 3  may be made of rubber 
     Referring to  FIGS. 2A-2D , a block mold  120  including bottom pressure plate  132  and dowels  130  is configured to receive first a front optical insert  121  followed by a front optical insert gasket  122 , the frame front  101 , a back optical insert gasket  123  and a back optical insert  124 . A protractor insert  125  is placed over the back optical insert  124 . In this manner, the frame front  101 , inserts  121 ,  124  and gaskets  122 ,  123  are sandwiched between top and bottom pressure plates  125 ,  132 , wherein the protractor insert acts as the top pressure plate  125 . 
     The same components are used for a second lens for the other side of the ophthalmic eyewear frame  100 . 
     The lenses  107  in the ophthalmic eyewear of the present invention include a range from approximately +20.00 diopters to −20.00 diopters of spherical power and up to 6.00 diopters of cylinder power for the correction of astigmatism. The lenses  107  are configured to be single vision or bifocal. Progressive addition lenses may be provided for the correction of presbyopia. The front optical insert  121  contains the spherical, bifocal or progressive addition geometry. The bifocal or progressive addition front optical insert  121  is positioned to be at the bottom of the lens for a near vision or reading visual path. The back optical insert  124  is spherical or cylindrical. The cylindrical back optical insert  124  is rotated to create the proper axis for the correction of astigmatism. The front optical inserts  121  may be manufactured from glass, metal or one of a number of formulations of plastic to which the monomer blend containing initiators and/or catalysts will not adhere when polymerized. In one embodiment, polypropylene is employed. In some embodiments, the inserts may be formed to allow the transmission of UV light. The eyeglass frame may be formed using any suitable frame material. By way of example, a Delrin® eyeglass frame (using virgin polyacetal) may be employed such that the monomer does not adhere to it when polymerized. 
     In accordance with some embodiments of the invention, the lenses are made of a monomer that can be cured by thermal energy or electromagnetic radiation. By way of example, near ultraviolet and polychromatic white light and/or sunlight may be employed. 
     B. Methods of Fabricating 
     The lenses in the ophthalmic eyewear of the present invention are produced by filling a cavity with a monomer blend containing initiators and/or catalysts. With reference to  FIGS. 2A-2D , the cavity is created by the frame front  101 , front and back optical insert gaskets  122 ,  123  and front and back optical inserts  121 ,  124 . In some embodiments, the monomer contains at least one photoinitiator that is designed to be reactive to the wavelength of light selected for the curing station. For example, near ultraviolet and polychromatic white light may be used. Alternatively, curing or polymerizing in situ on the eyeglass frame can be achieved by the controlled application of heat. 
     The mold is assembled by selecting a front optical insert  121  from a look up table or software program that directs the user to the proper radius front surface mold for a given lens prescription based on the index of refraction of the cured polymer. The front optical insert  121  is placed with the usable concave side facing upward. A front insert gasket  122  is then placed in the recesses of the front optical insert  121  followed by placing the frame front  101  against the front optical insert  121 . Subsequently, a back optical insert gasket  123  is selected from a look up table or software program that directs the user to the proper gasket thickness for a given lens prescription. A back optical insert  124  is then selected from a look up table or software program that directs the user to the proper back optical insert for a given lens prescription. The back optical insert  124  is placed on the back optical insert gasket  123  with its usable convex surface facing the concave surface of the front optical insert  121 . The protractor retaining device  125  is then mounted over the back optical insert  124 . The cylindrical back optical insert  124  contains a scribe mark on the back surface of the insert that is aligned with the axis of the cylinder. The back optical insert  124  is rotated to align the scribe mark of the axis indicated by the look up table or software program that directs the user for a given lens prescription with the indicated degree orientation on the protractor. 
     The procedure is repeated for the corresponding second lens in the ophthalmic eyewear frame front  101 . 
     With reference to  FIGS. 1A and 1B , the monomer blend containing initiators and/or catalysts is directed into the cavity through one capillary tube  105  in the capillary housing  106  of the first lens cavity in a manner that allows the air to release through the alternate capillary tube  105  in the same capillary housing  106 . As disclosed herein, the capillary tubes  105  are capable of retaining a volume in excess of the shrinkage that occurs during the monomer blend polymerization and prevent the formation of an air bubble in the lens  107  by retracting liquid monomer into the prescription lens as required. Alternatively, a chamber other than a capillary tube may be provided to retain an additional about 2-5% of the volume of the lens  107 . When all the air is released and the liquid monomer begins to express from the air relief capillary tube, the cavity filling is complete. After both cavities are filled, the mold assembly  120  (with the eyewear, gaskets, inserts and filled cavities) is transferred to the curing station and the cavities are exposed to the proper light source for the prescribed period to initiate and complete the polymerization of the lenses  107 . Alternatively, the curing or polymerizing in situ on the eyeglass frame can be achieved by the controlled application of heat or exposure to sunlight. 
     Referring again to  FIGS. 2A-2D , the block mold  120  is then opened by reversing the steps for the assembly of the mold. The closure mechanism is removed, followed by the protractor insert  125 . The eyewear  100  is removed with the front and back optical inserts  121 ,  124  and gaskets  122 ,  123  attached. The front optical insert  121  and gasket  122  are removed by applying a deforming pressure at the junction of the frame  101  and the front optical insert  121  and allowing air to pass between the optical insert and the polymerized lens. The front insert  121  is then released and the procedure is repeated for the back optical insert  124 . The procedure is repeated for the second ophthalmic eyewear lens. 
     The next steps involve detaching the capillary tubes  105  from the rim of the frame front and attaching the conventional earpieces to the end-pieces  103  of the eyewear frame front  101 . One suitable material for the block mold  120  is soft polyvinyl chloride (PVC). 
     C. Additional Embodiments 
     A further embodiment of the invention comprises a one-piece block mold that is prepared in the form of the frame. In particular, a front optical insert and front optical insert gasket are assembled to the block mold cavity having the configuration to form the front half of the frame followed by the assembly of the back mold half having the configuration to form the back half of the frame. The back optical insert gasket is assembled to the back frame half cavity and the back optical insert is assembled. Subsequently, a protractor insert is assembled and the axis of the back optical insert is adjusted followed by the mold closure device. 
     Referring to  FIGS. 3A-3E , the one-piece block mold  400  comprises top plate  500 , bottom plate  600  and dowels  610  configured to receive the back optical insert  602  followed by the back optical insert gasket  601 , the top plate  500 , a front optical insert gasket  501  and a front optical insert  502 . The top plate  500  is dimensioned to form the back half of the frame front  101  of  FIGS. 1A and 1B  including bridge or nose piece  102 , end-pieces  103  and a pair of eyewire portions  104  for holding lenses  107 . The back plate  600  is dimensioned to form the front half of the frame front  101  of  FIGS. 1A and 1B  including bridge or nose piece  102 , end-pieces  103  and a pair of eyewire portions  104  for holding lenses  107 . Additionally, two capillary tubes  603  (for each lens  107 ) are provided within the top plate  500  such that the capillary tubes  603  are in fluid communication with the interior side of the front mold  500  and the back mold  600 . The capillary tubes  603  act to hold a volume of liquid monomer for the liquid lenses  107  during formation. In particular, the capillary tubes  603  are capable of retaining a volume in excess of the shrinkage that occurs during the monomer blend polymerization. In addition, the capillary tubes  603  prevent the formation of an air bubble in the lens  107  by retracting liquid monomer into the prescription lens as required. In further embodiments, a chamber other than a capillary tube may be provided to retain an additional about 2-5% of the volume of the lens  107 . 
     Referring now to  FIGS. 4A-4D , according to further embodiments of the invention, an alternate frame in the form of a three piece mount  190  comprises a bridge  200  that is cast into the right and left spectacle lens, and left and right end-piece  300  that are cast into the lateral aspect of each of the spectacle lenses. The bridge  200  comprises an arch  201  and adjustable nose pads  202 , an extension  203  that is cast into the lens, and a seal  204  that conforms to an aperture  401  in gasket  400 , which retains the front and back optical inserts  410 ,  412 . The end-pieces  300  are comprised of an extension  304  that is cast into the lens, a face portion  301 , a hinge portion  302  and a seal  303  that conforms to another aperture  408  in the gasket  400 . A single gasket  400  with two apertures  401 ,  408  for the bridge  200  and end-piece  300  is used for each lens. The gasket  400  comprises recesses  402  for each of the front and back optical inserts  410 ,  412 . A series of gaskets is utilized, each having a different separation distance between the seating position of the front and back optical inserts. The proper gasket is selected from a look up table or software program that directs the user to the proper gasket for a given lens prescription. 
     With further reference to  FIGS. 4A-4D , the optical insert gasket  400  is configured with a housing  403  with two capillary tubes  414 ,  416  for filling the mold cavity with the monomer blend containing initiators and/or catalysts and for the release of air from the cavity. Similar to previous embodiments, the capillary tubes  414 ,  416  are capable of retaining a volume in excess of the shrinkage that occurs during the monomer blend polymerization and prevent the formation of an air bubble in the lens by retracting liquid monomer into the prescription lens as required. Alternatively, a chamber other than a capillary tube may be provided to retain an additional about 2-5% of the volume of the lens. 
     One skilled in the art will appreciate that the present invention can be practiced by other than the various embodiments and preferred embodiments, which are presented in this description for purposes of illustration and not of limitation, and the present invention is limited only by the claims that follow. It is noted that equivalents for the particular embodiments discussed in this description may practice the invention as well. 
     While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not of limitation. Likewise, the various diagrams may depict an example architectural or other configuration for the invention, which is done to aid in understanding the features and functionality that may be included in the invention. The invention is not restricted to the illustrated example architectures or configurations, but the desired features may be implemented using a variety of alternative architectures and configurations. Indeed, it will be apparent to one of skill in the art how alternative embodiments may be implemented to achieve the desired features of the present invention. Also, a multitude of different constituent part names other than those depicted herein may be applied to the various parts of the devices. Additionally, with regard to operational descriptions and method claims, the order in which the steps are presented herein shall not mandate that various embodiments be implemented to perform the recited functionality in the same order unless the context dictates otherwise. 
     Although the invention is described above in terms of various exemplary embodiments and implementations, it should be understood that the various features, aspects and functionality described in one or more of the individual embodiments are not limited in their applicability to the particular embodiment with which they are described, but instead may be applied, alone or in various combinations, to one or more of the other embodiments of the invention, whether or not such embodiments are described and whether or not such features are presented as being a part of a described embodiment. Thus the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments. 
     Terms and phrases used in this document, and variations thereof, unless otherwise expressly stated, should be construed as open ended as opposed to limiting. As examples of the foregoing: the term “including” should be read as meaning “including, without limitation” or the like; the term “example” is used to provide exemplary instances of the item in discussion, not an exhaustive or limiting list thereof; the terms “a” or “an” should be read as meaning “at least one,” “one or more” or the like; and adjectives such as “conventional,” “traditional,” “normal,” “standard,” “known” and terms of similar meaning should not be construed as limiting the item described to a given time period or to an item available as of a given time, but instead should be read to encompass conventional, traditional, normal, or standard technologies that may be available or known now or at any time in the future. Likewise, where this document refers to technologies that would be apparent or known to one of ordinary skill in the art, such technologies encompass those apparent or known to the skilled artisan now or at any time in the future. 
     A group of items linked with the conjunction “and” should not be read as requiring that each and every one of those items be present in the grouping, but rather should be read as “and/or” unless expressly stated otherwise. Similarly, a group of items linked with the conjunction “or” should not be read as requiring mutual exclusivity among that group, but rather should also be read as “and/or” unless expressly stated otherwise. Furthermore, although items, elements or components of the invention may be described or claimed in the singular, the plural is contemplated to be within the scope thereof unless limitation to the singular is explicitly stated. 
     The presence of broadening words and phrases such as “one or more,” “at least,” “but not limited to” or other like phrases in some instances shall not be read to mean that the narrower case is intended or required in instances where such broadening phrases may be absent.