Patent Publication Number: US-2021177575-A1

Title: Intraocular lens having increased optic diameter

Description:
PRIORITY CLAIM 
     This application claims the benefit of priority of U.S. Provisional Patent Application Ser. No. 62/949,041 titled “INTRAOCULAR LENS HAVING INCREASED OPTIC DIAMETER,” filed on Dec. 17, 2019, whose inventor is Mark Andrew Zielke, which is hereby incorporated by reference in its entirety as though fully and completely set forth herein. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to intraocular lens (IOL) lens designs. 
     BACKGROUND 
     The human eye includes a cornea and a crystalline lens that are intended to focus light that enters the pupil of the eye onto the retina. However, the eye may exhibit various refractive errors, which result in light not being properly focused upon the retina, and which may reduce visual acuity. Many interventions have been developed over the years to correct various ocular aberrations. These include spectacles, contact lenses, corneal refractive surgery, such as laser-assisted in situ keratomileusis (LASIK) or corneal implants, and IOLs. IOLs are also used to treat cataracts by replacing the natural diseased crystalline lens of the eye of a patient. During typical IOL-placement surgery, an IOL is inserted into the capsular bag of a patient to replace the natural crystalline lens. 
     To insert an IOL into the eye, a foldable intraocular lens is inserted through the temporal clear corneal incision, often using a specially designed lens injector. The incision size is normally approximately 4 mm or less, and, with injectable IOLs, it may be approximately 3 mm or less. 
     The most common IOLs include an edge-to-edge optic that is approximately 6.0 mm in diameter. Visual disturbances caused by interaction of light with the edge of the optic or by light missing the edge of the optic are among problems some patients experience with a 6.0 mm lens. These visual disturbances may be reduced with a larger diameter lens, but as the diameter of an IOL increases, the volume of the IOL also increases, necessitating a larger incision. When the volume of the IOL becomes excessive, the IOL may not be insertable through a sufficiently small incision in the capsular bag. 
     SUMMARY 
     In one aspect, the present disclosure is directed to an intraocular lens, including an optic with an anterior surface and a posterior surface surrounded by an optic edge. The IOL may also include a plurality of haptics, each attached to the optic at a gusset, where each gusset extends beyond the optic edge toward an optic center such that the gusset at least partially overlaps with the anterior surface of the optic. 
     The IOL may include one or more of the following additional features: (i) the gusset may vary in thickness between a radially innermost edge and the haptics; (ii) the gusset may increase in thickness as it extends from a radially innermost edge away from the optic center; (iii) the gusset may have a zero thickness at a radially innermost edge and increase to a first thickness at a point radially beyond the optic edge; (iv) the gusset may have a thickness that increases monotonically as the gusset extends outwardly; (v) the optic may have a maximum thickness that is less than the thickness of the haptic; (vi) the radially innermost edge of the gusset may be at least 2.75 mm from the optic center; (vii) the optic may have a diameter between 6 mm and 8 mm, and the IOL may have a total volume between 19 mm3 and 48 mm3; (viii) the optic edge may have a thickness between 0.05 mm and 0.3 mm; (ix) the optic may have a diameter of 6 mm, and the IOL may have a total volume between 19 mm3 and 23 mm3; (x) the optic edge may have a thickness of 0.25 mm; (xi) a 21 Diopter IOL may have a total volume of 19 mm3; (xii) a 30 Diopter IOL may have a total volume of 23 mm3; (xiii) the optic may have a diameter of 7 mm, and the IOL may have a total volume between 23 mm3 and 30 mm3; (xiv) the optic edge may have a thickness of 0.1 mm; (xv) a 21 Diopter IOL may have a total volume of 23 mm3; (xvi) a 30 Diopter IOL may have a total volume of 30 mm3; xvii) the optic may have a diameter of 8 mm, and the IOL may have a total volume between 35 mm3 and 48 mm3; (xviii) the optic edge may have a thickness of 0.1 mm; (xix) a 21 Diopter IOL may have a total volume of 35 mm3; (xx) a 30 Diopter IOL may have a total volume of 48 mm3; (xxi) the optic and haptics may be made of a soft, foldable optic material; (xxii) the optic, gusset, and haptics are integrally formed to comprise a single-piece IOL. 
     In another aspect, an IOL comprises an optic comprising an anterior surface and a posterior surface disposed about an optical axis, the anterior surface and posterior surface surrounded by an optic edge connecting the anterior surface to the posterior surface, the optic edge defining a circumference of the optic. A gusset connects at least one haptic to at least one of the anterior surface and the posterior surface, the gusset extending from a radially innermost gusset edge to a gusset-haptic junction. The gusset at least partially overlaps with the at least one of the anterior surface and the posterior surface of the optic. 
     The IOL may include one or more of the following additional features: (i) the at least one of the anterior surface and the posterior surface comprises an optically active region configured to focus light to one or more focal points and a peripheral region surrounding the optically active region; and wherein the radially innermost gusset edge is in the peripheral region; (ii) the anterior surface and the posterior surface each comprise optically active regions configured to focus light to one or more focal points, each of the optically active regions extending from the center of the optic to the optic edge; (iii) the gusset protrudes from the at least one of the anterior surface and the posterior surface of the optic; (iv) the gusset protrudes from only one of the anterior surface and the posterior surface of the optic such that a cross section of the gusset is asymmetric with respect to a plane orthogonal to the optical axis; (v) the gusset increases in thickness as it extends outwardly from the innermost gusset edge; (vi) the gusset has a zero thickness at the gusset edge and increases to a maximum thickness outside the optic edge; (vii) the gusset has a thickness that increases monotonically as the gusset extends radially outwardly; (viii) a maximum thickness of the optic is less than a maximum thickness of the haptic; (ix) the radially innermost edge of the gusset is at least 2.75 mm from the optic center; (x) the optic has a diameter between 6 mm and 8 mm and the IOL has a total volume between 19 mm3 and 48 mm3; (xi) the optic edge has a thickness between 0.05 mm and 0.3 mm; (xii) the optic has a diameter of 6 mm and the IOL has a total volume between 19 mm3 and 23 mm3; (xiii) the optic edge has a thickness of 0.25 mm; (xiv) a 21 Diopter IOL has a total volume of 19 mm3; (xv) a 30 Diopter IOL has a total volume of 23 mm3; (xvi) the optic has a diameter of 7 mm and the IOL has a total volume between 23 mm3 and 30 mm3; (xvii) the optic edge has a thickness of 0.1 mm; (xviii) a 21 Diopter IOL has a total volume of 23 mm3; (xix) a 30 Diopter IOL has a total volume of 30 mm3; (xx) the optic has a diameter of 8 mm and the IOL has a total volume between 35 mm3 and 48 mm3; (xxi) the optic edge has a thickness of 0.1 mm; (xxii) a 21 Diopter IOL has a total volume of 35 mm3; (xxiii) a 30 Diopter IOL has a total volume of 48 mm3; (xxiv) the optic, gusset, and haptics are made of a soft, foldable biocompatible material; (xxv) the optic, gusset, and haptics are integrally formed to comprise a single-piece IOL. 
     In another aspect, the present disclosure is directed to an IOL, including an optic having an optic edge. The IOL may also include a ring structure integral with the optic and surrounding the perimeter of the optic edge. Both the ring structure and the optic edge may have a thickness, and the ring structure thickness may be greater than the optic edge thickness. The IOL may also include a plurality of haptics attached to the ring structure. 
     The IOL may include one or more of the following additional features: (i) a step between the optic edge and the ring structure; (ii) the step may be angled, vertical, square, or rounded; (iii) the haptic and ring structure may attach at a haptic-ring junction that may have a thickness which may increase in thickness from the ring structure thickness to a point radially beyond the ring structure; (iv) the haptic-ring junction thickness may increase monotonically as it extends outwardly; (v) a maximum thickness of the optic may be less than the ring structure thickness; (vi) the optic, ring structure, and haptics may be made of a soft, foldable optic material; (vii) the optic may have a diameter between 6 mm and 8 mm, and the IOL may have a total volume between 14 mm3 and 48 mm3; (viii) the optic may have a diameter of 6 mm, and the IOL may have a total volume between 14 mm3 and 18 mm3; (ix) the optic may have a diameter of 7 mm, and the IOL may have a total volume between 23 mm3 and 30 mm3; (x) the optic may have a diameter of 8 mm, and the IOL may have a total volume between 35 mm3 and 48 mm3; (xi) the optic edge thickness may be between 0.05 mm and 0.3 mm; (xii) the optic edge thickness may be 0.15 mm; viii) the ring structure thickness may be between 0.2 mm and 0.5 mm; (xiv) the optic may be made of a first material, and the ring structure and haptics may be made of a second material. The second material may have a higher stiffness than the first material; (xv) the first material may be a soft, foldable optic material; (xvi) the first material may be Acrysof, p-hydroxyethyl methacrylate, a hydrophobic silicon polymer, acrylates, or hydrophilic 2-HEMA homopolymers; xvii) the second material may be Poly(methyl methacrylate) (p-MMA), polyvinylidene fluoride (PVDF), polysulfones, or an acrylic; (xviii) the ring structure and the haptics may be molded or bonded to the optic edge; (xix) the optic may have a diameter between 6 mm and 8 mm, and the IOL may have a total volume between 13 mm3 and 46 mm3; (xx) the optic may have a diameter of 6 mm, and the IOL may have a total volume between 13 mm3 and 17 mm3; (xxi) the optic may have a diameter of 7 mm, and the IOL may have a total volume between 21 mm3 and 28 mm3; (xxii) the optic may have a diameter of 8 mm, and the IOL may have a total volume between 34 mm3 and 46 mm3. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present disclosure, reference is now made to the following description, taken in conjunction with the accompanying drawings illustrating aspects of the present disclosure, in which like components have like numerals, including with alphabetic designations of variants, such as  10   a,    10   b,  and in which: 
         FIG. 1A  is a top view of the anterior surface of an IOL, where the gusset extends beyond the optic edge toward an optic center, partially overlapping with the anterior surface of the optic. 
         FIG. 1B  is a perspective view of an IOL, where the gusset extends beyond the optic edge toward an optic center, partially overlapping with the anterior surface of the optic. 
         FIG. 1C  is an enlarged view of a gusset of an IOL, where the gusset extends beyond the optic edge toward an optic center, partially overlapping with the anterior surface of the optic. 
         FIG. 1D  is an enlarged view of a gusset of an IOL, where the gusset extends beyond the optic edge toward an optic center, partially overlapping with the anterior surface of the optic. 
         FIG. 2A  is a perspective view of an IOL having a ring structure around the perimeter of the optic edge. 
         FIG. 2B  is a cross-section view of an IOL having a ring structure around the perimeter of the optic edge. 
         FIG. 2C  is a perspective cross-section view of an IOL having a ring structure around the perimeter of the optic edge. 
         FIG. 3A  is a top view of an IOL having a ring structure around the perimeter of the optic edge, where the optic is a different material than the ring structure and haptics. 
         FIG. 3B  is a perspective view of an IOL having a ring structure around the perimeter of the optic edge, where the optic is a different material than the ring structure and haptics. 
         FIG. 3C  is a perspective view of an IOL having a ring structure around the perimeter of the optic edge, where the optic is a different material than the ring structure and haptics. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure relates to an IOL, where the diameter of the IOL is increased without significantly increasing the overall volume. This may be achieved by using gussets to connect the optic to the haptic. Each gusset may originate on the anterior or posterior surface of the optic itself (rather than at the optic edge) and extend radially outwardly toward the haptic, thus partially overlapping with the anterior (or posterior) surface of the optic. The gusset may be located outside an optically active area of the optic (e.g., beyond 2.5-3 mm from the optic center) to minimize the possibility of an adverse impact on a patient&#39;s vision. Alternatively, the entire posterior and/or anterior surfaces of the optic may be optically active. (An optically active area of the IOL may include one or more surface profiles on the anterior and/or posterior surfaces of the optic which are collectively configured to focus light at one or more focal points to provide vision correction for a patient.) By coupling the haptics with a gusset connected on the anterior or posterior surface of the optic, the optic edge is not required to support the haptic structurally. Accordingly, the optic can be made thinner, reducing overall volume even with relatively large optics (e.g., having a diameter greater than 6 mm). 
     Such benefits may alternatively or, when appropriate, additionally be achieved by using a ring structure around the perimeter of the optic edge, where the ring structure may be made of the same material as the optic or may be made of a second material having a higher stiffness than a first material of which the optic is made. 
     In  FIGS. 1A-D , the anterior surface of an IOL  100  is shown having an optic  110  and two haptics  120  attached to optic  110  by gussets  130 . 
     Optic  110  has an anterior surface and a posterior surface (not shown) that are connected and surrounded by an optic edge  140 . By decreasing the thickness of optic  110  at and approaching optic edge  140 , the overall volume of IOL  100  may be decreased (thickness being measured anteriorly-to-posteriorly along the optical axis (OA)). For example, the thickness of optic  110  at its centermost point, optic center  160  (the point of maximum thickness for a biconvex lens), may be between 0.2 mm and 2 mm, while optic edge 140 may have a thickness between 0.05 mm and 0.3 mm. The thickness of optic  110  may vary based on the materials used for optic  110 . For example, a stiffer material may have an optic edge  140  having a thickness of between 0.05 mm and 0.1 mm, while a softer material may have an optic edge  140  having a thickness of between 0.1 mm and 0.3 mm. The maximum thickness of optic  110  may be less than the thickness of haptics  120  (thickness being measured along the optical axis of the optic). 
     One or more haptics  120  connect optic  110  to a capsular bag to hold optic  110  in a stable position within the capsular bag. The embodiment shown in  FIGS. 1A-D  shows an IOL having two, open-loop haptics, but the number and shape of the haptics may vary. The number of haptics may include, but are not limited to, one, two, three, four, five, or six. The shape of the haptics may include, but are not limited to, plate, open-loop, such as C-Loop or J-Loop, angular, planar, or off-set haptics. The overall length of IOL  100 , including haptics, may be between 10 mm and 15 mm. The thickest portion of haptics  120  (thickness being measured along an axis parallel to the optical axis of the lens) may be between 0.2 mm and 1 mm. For example, the thickest part of haptics  120  may be 0.6 mm. 
     The gussets  130  (shown in more detail in  FIGS. 1C and 1D ) attach optic  110  to the two haptics  120 . Each gusset  130  extends radially inward from the haptic  120 , across optic edge  140 , and toward optic center  160 , such that gusset  130  at least partially overlaps with and extends onto the anterior surface of the optic  110 . Gussets  130  each have a radially innermost edge  150  located on the anterior surface of IOL  100  radially inwardly from where optic edge  140  would be if the gussets  130  were not present. Radially innermost edge  150  of gusset  130  may be between 2.5 mm and 3 mm in a radially outward direction from optic center  160  to prevent obstruction of a patient&#39;s vision. For example, radially innermost edge  150  of gusset  130  may be 2.75 mm radially outwardly from optic center  160  in some embodiments, such that the distance across the optic from one gusset edge  150  to the other is 5.5 mm. Radially innermost edge  150  of gusset  130  may be between 0.1 and 1.5 mm in a radially inwardly direction from a distance corresponding to optic edge  140  (i.e., where optic edge  140  would be if not for the presence of gusset  130 ). For example, radially innermost edge  150  of gusset  130  may be 1.25 mm radially inward from optic edge  140 . 
     In some examples, an optical surface profile defining an optically active area of the anterior and/or posterior surface of optic  110  (e.g., a spherical or aspheric monofocal, multifocal, or extended depth of focus surface profile) may extend continuously from optic center  160  to optic edge  140  (excepting areas where gussets  130  impinge). In other examples, the optical surface profile defining an optically active area of the anterior and/or posterior surface may extend radially from optic center  160  a distance between optic center  160  and optic edge  140 , e.g., about 2.5 to 3 mm radially from optic center  160 . In such examples, a peripheral area  115  of the anterior surface outside the optical surface profile may have a different surface profile than the central area of optic  110 . For example, a profile of such a peripheral area  115  may be flat or may have a thickness which varies differently than the optic surface profile. In examples which include a peripheral area  115 , the peripheral area  115  may be separated from the optically active area at a boundary  118 , which may be visibly perceptible or not. In examples which do not include a peripheral area  115 , boundary  118  is not present. 
     Gusset  130  may vary in thickness between radially innermost edge  150  and haptics  120 . Radially innermost edge  150  may be level or flush with optic  110  at radially innermost edge  150 , having zero thickness. As gusset  130  extends from radially innermost edge  150  radially outwardly away from optic center  160 , the thickness of gusset  130  may increase monotonically. The thickness may continue to increase to a first peak thickness  135  located at a point radially outward from optic edge  140 . 
     In conventional IOLs, haptics are connected to an optic at a haptic-optic junction along a perimeter of the optic edge. This design necessitates a threshold edge thickness for the stability of this connection. Due to the required edge thickness, extending the optic to larger diameters (e.g., beyond 6 mm) increases volume to a degree that makes small-incision delivery (e.g., 2-3 mm incisions or smaller) difficult or impossible. 
     In the disclosed design, however, that gusset  130  connecting optic  110  and haptic  120  at least partially overlaps with the anterior and/or posterior surface of optic  110 , thus using part of the anterior surface for a haptic-optic connection rather than only the perimeter of the optic edge. Accordingly, gusset  130  may protrude from the anterior and/or posterior surface of the optic. In some examples, gusset  130  protrudes from only one of the anterior or posterior surface, and is flush on the opposite surface. 
     As a result, the diameter of optic  110  may be increased relative to a conventional optic, while corresponding increases in volume are minimized so that the IOL may still be inserted through a small incision. In various examples, the volume of optic  110  may be between 10 mm3 and 40 mm3. 
     Optic  110  may have a diameter in the range of 6 to 8 mm. In some embodiments, the diameter of optic  110  may be 6 mm, 7 mm, or 8 mm, and the total volume of the IOL may be between approximately 19 mm3 and 48 mm3. The thickness of optic edge  140  may range between approximately 0.05 mm3 and 0.3 mm3. 
     In a 6 mm optic diameter embodiment, optic edge  140  may have a thickness of 0.25 mm. In this embodiment, IOL  100  may have a total volume between 19 mm3 and 23 mm3. For example, a 21 diopter IOL may have a total IOL volume of 19 mm3, and a 30 diopter IOL may have a total IOL volume of 23 mm3. 
     In a 7 mm optic diameter embodiment, optic edge  140  may have a thickness of 0.1 mm. In this embodiment, IOL  100  may have a total volume between 23 mm3 and 30 mm3. For example, a 21 diopter IOL may have a total IOL volume of 23 mm3, and a 30 diopter IOL may have a total IOL volume of 30 mm3. 
     In an 8 mm optic diameter embodiment, optic edge  140  may have a thickness of 0.1 mm. In this embodiment, IOL  100  may have a total volume between 35 mm3 and 48 mm3. For example, a 21 diopter IOL may have a total IOL volume of 35 mm3, and a 30 diopter IOL may have a total IOL volume of 48 mm3. 
     IOL  100  may be inserted through an incision of between 1 mm and 3 mm. It is important to maintain a small incision because too large of an incision may lead to a flattening effect of the cornea. Furthermore, a smaller incision may be better able to seal after surgery to prevent leakage and tear film contamination. Quicker sealing of the incision may help prevent or reduce the risk of developing surgically induced astigmatism or endophthalmitis. Because fluid flow is related to the size of the phaco needle, using sub-1 mm incisions reduces the flow rate and makes surgery significantly slower. Incisions more than 3 mm tend to have a greater flattening effect on the cornea at that meridian. In addition, the incision should be small enough to seal effectively after the surgery to prevent leakage as well as tear film influx, which could increase the risk of endophthalmitis. So, the ideal incision size for cataract surgery is between 1 mm and 3 mm, which is small enough to reduce astigmatic effect from the incision and the risk of infection due to leakage or tear film contamination. 
     Optic  110 , haptics  120 , and gussets  130  may be made of a soft, foldable optic material, or of any material suitable to be a lens, while also providing sufficient mechanical support. For example, the material may be hydrogel, acrylate, or silicon-based material, as known in the field of ophthalmology. 
     In another embodiment, as shown in  FIGS. 2A-C , the present disclosure relates to an IOL  200  having a ring structure  210  integral with the optic  205  and surrounding the perimeter of the optic edge  240 . Adding the stiff, outer ring structure  210  allows for a thinner optic  205 , which reduces the overall volume of the IOL  200 . The optic  205  may be thinner because the ring structure  210  provides a base and mechanical support for the haptics  220  in lieu of the optic  205  providing the base and mechanical support. 
     In  FIG. 2A , IOL  200  is shown having a ring structure  210  around the perimeter of optic edge  240 . The ring structure  210  may be thicker than the optic edge  240  and may be between 0.2 mm and 0.5 mm. For example, the thickness of the ring structure  210  may be 0.3 mm. 
     Between the optic edge and ring structure, IOL  200  may include a step. The shape of the step  200  may be, must is not limited to, angled, vertical, square, or round. 
     A plurality of haptics  220  may attach to the ring structure  210  at opposite sides at a haptic-ring junction. At the point of connection  230  (shown in  FIG. 2C ), the haptic-ring junction may by the same thickness as the ring structure  210 , and then may increase in thickness from the ring structure thickness to a point radially beyond the ring structure. The haptic-ring junction thickness may increase monotonically as it extends outwardly. The embodiment shown in  FIG. 2A  shows an IOL having two, open-loop haptics, but the number and shape of the haptics may vary. The number of haptics may include, but are not limited to, two, three, four, five, or six. The shape of the haptics may include, but are not limited to, plate, open-loop, such as C-Loop or J-Loop, angular, planar, or off-set haptics. 
       FIGS. 2B-C  show cross sections of IOL  200 . In embodiments, the thickness of optic edge  240  may be between 0.05 mm and 0.3 mm. For example, the thickness of optic edge  240  may be 0.15 mm. The maximum thickness of optic  205  at its center  250  may be less than the ring structure thickness. The thickness of optic  205  at its center  250  depends on the IOL power, material refractive index, and other IOL geometry. In embodiments, the thickness of optic  205  at its center  250  may be between 0.2 mm and 2 mm. 
     Reducing the overall lens thickness allows for a larger optic diameter without increasing the volume. So, optic  205  may have a larger diameter than a conventional optic, while maintaining an acceptable volume that may still insert through a small incision. Ring structure  210  having a thinner optic  205  provides for an IOL  200  with a volume that may fit through a small incision. For example, IOL  200  may be inserted through an incision of between 1 mm and 3 mm. The diameter of the optic  205  may be between 6 mm and 8 mm. In some embodiments, the diameter of the optic may be 6 mm, 7 mm, or 8 mm, and the total volume of IOL  200  may be between approximately 14 mm3 and 48 mm3. 
     In a 6 mm optic diameter embodiment, optic edge  240  may have a thickness of 0.1 mm. In this embodiment, IOL  200  may have a total volume between 14 mm3 and 18 mm3. For example, a 21 diopter IOL may have a total IOL volume of 14 mm3, and a 30 diopter IOL may have a total IOL volume of 18 mm3. 
     In a 7 mm optic diameter embodiment, optic edge  240  may have a thickness of 0.1 mm. In this embodiment, IOL  200  may have a total volume between 23 mm3 and 30 mm3. For example, a 21 diopter IOL may have a total IOL volume of 23 mm3, and a 30 diopter IOL may have a total IOL volume of 30 mm3. 
     In an 8 mm optic diameter embodiment, optic edge  240  may have a thickness of 0.1 mm. In this embodiment, IOL  200  may have a total volume between 35 mm3 and 48 mm3. For example, a 21 diopter IOL may have a total IOL volume of 35 mm3, and a 30 diopter IOL may have a total IOL volume of 48 mm3. 
     Optic  205 , ring structure  210 , and haptics  220  may be the same material. Using the same material for the entire IOL  200  allows the entire IOL  200  to be formed together. This may eliminate a need for bonding or overmolding of the components. The material used for optic  205 , ring structure  210 , and haptics  220  may be a soft, foldable optic material. The softer material may have a modulus of 6 MPa or lower at 35° C. For example, the material may be hydrogel, acrylate, or silicon-based material, as known in the field of ophthalmology. 
     In another embodiment, as shown in  FIGS. 3A-C , the present disclosure relates to an IOL  300  having a ring structure  310  around the perimeter of the optic edge  340 , where the optic  305  is a different material than ring structure  310  and haptics  320 . For example, optic  305  may be made of a first material, and ring structure  310  and haptics  320  may be made of a second material. The stiffness of ring structure  310  may provide support for the softer optic  305 . Optic  305  and ring structure  310  may be attached via bonding or overmolding. Bonding or overmolding are processes where a single part is created using two or more different materials in combination. For example, first an optic  305  may be molded. Then ring structure  310  and haptics  320  may be molded onto or around optic  305 . 
     Optic  305  may be made of a first material. For example, it may be made of a soft, foldable optic material. By way of example, optic  305  may be made of Acrysof, p-hydroxyethyl methacrylate, a hydrophobic silicon polymer, acrylates, or hydrophilic 2-HEMA homopolymers. In embodiments, optic  305  may be made of a soft acrylate. 
     Ring structure  310  and haptics  320  may be made of a second material. For example, ring structure  310  and haptics  320  may be made of a stiffer material than optic  305 , removing the need for a thicker optic edge  340 . Using a stiffer material for ring structure  310  and haptics  320  can lower the overall IOL  300  volume to help with small delivery incision and allow IOL  300  to be inserted through an incision of between 1 mm and 3 mm. Ring structure  310  and haptic  320  materials may have suitable strength and stiffness characteristics to provide stability in a capsular bag while remaining foldable, allowing for delivery through a small incision in the capsular bag. A stiffer material resists deformation in response to an applied force, as compared to a more flexible material. The stiffer material may have a modulus at least 30% higher than the modulus of the softer material. In embodiments, the stiffer material may have a modulus of 7.8 MPa or higher at 35° C. Ring structure  310  and haptics  320  may be made of a second material, such as a stiff haptic material, including, for example, Poly(methyl methacrylate) (p-MMA), polyvinylidene fluoride (PVDF), polysulfones, an acrylic, or of any material having a suitable stiffness to support the optic  305 , while still being foldable. 
     In embodiments, ring structure  310  and optic edge  340  may be the same thickness. The thickness of ring structure  310  and optic edge  340  may be between 0.05 mm and 0.25 mm. For example, ring structure  310  and optic edge  340  may be 0.15 mm. 
     In other embodiments, ring structure  310  may be thicker than optic edge  340 . The thickness of ring structure  310  may be between 0.1 mm and 0.5 mm. For example, the thickness of ring structure  310  may be 0.15 mm. The thickness of optic edge  340  may be between 0.05 mm and 0.3 mm. The ring structure  310  may be between 30% and 500% times thicker than the optic edge  340 . 
     The diameter of optic  305  may be 6 mm to 8 mm. In some embodiments, the diameter of optic  305  may be 6 mm, 7 mm, or 8 mm, and the total volume of IOL  300  may be between 13 mm3 and 46 mm3. 
     In a 6 mm optic diameter embodiment, optic edge  340  may have a thickness of 0.1 mm. In this embodiment, IOL  300  may have a total volume between 13 mm3 and 17 mm3. For example, a 21 diopter IOL may have a total IOL volume of 13 mm3, and a 30 diopter IOL may have a total IOL volume of 17 mm3. 
     In a 7 mm optic diameter embodiment, optic edge  340  may have a thickness of 0.1 mm. In this embodiment, IOL  300  may have a total volume between 21 mm3 and 28 mm3. For example, a 21 diopter IOL may have a total IOL volume of 21 mm3, and a 30 diopter IOL may have a total IOL volume of 28 mm3. 
     In an 8 mm optic diameter embodiment, optic edge  340  may have a thickness of 0.1 mm. In this embodiment, IOL  300  may have a total volume between 34 mm3 and 46 mm3. For example, a 21 diopter IOL may have a total IOL volume of 34 mm3, and a 30 diopter IOL may have a total IOL volume of 46 mm3. 
     The above disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments which fall within the true spirit and scope of the present disclosure. Thus, to the maximum extent allowed by law, the scope of the present disclosure is to be determined by the broadest permissible interpretation of the following claims and their equivalents and shall not be restricted or limited by the foregoing detailed description.