Method for manufacturing an ophthalmic lens including an asymmetric gradient index optic

Abstract

A method (100) for manufacturing an ophthalmic lens is described. The method includes providing a lens substrate (103) and providing a photocurable film (105). The method includes photocuring at least one region of the film using a digital light projection system (107), thereby producing a photocured gradient index optical element having an asymmetric refractive index profile. The method includes applying (109) the film to a surface of the lens substrate.

Description

[Technical field]

[0001] The present disclosure relates to a method of manufacturing an ophthalmic lens, comprising applying a film to a surface of the ophthalmic lens, the film including at least one gradient index optical element having an asymmetric refractive index distribution that is photocured using digital light projection (DLP) technology. [Background technology]

[0002] Many people, both children and adults, need ophthalmic lenses to correct myopia (a condition in which infinitely distant light rays are focused in front of the retina), and many adults need ophthalmic lenses to correct presbyopia (an age-related inability to accommodate and therefore focus on nearby objects). Ophthalmic lenses may also be needed to correct hyperopia (a condition in which infinitely distant light rays are focused behind the retina), astigmatism, or keratoconus (a condition in which the cornea bulges and assumes the shape of a cone).

[0003] Without optical correction, myopia focuses incoming light from distant objects to a location located in front of the retina. As a result, the light converges toward a plane located in front of the retina (beyond which it diverges) and then diverges toward the retina, becoming unfocused when it reaches the retina. Conventional lenses for correcting myopia (e.g., spectacle lenses or contact lenses) reduce the convergence (with contact lenses) or cause divergence (with spectacle lenses) of the incoming light from distant objects before it reaches the eye, so that the location of the focus is shifted onto the retina.

[0004] In presbyopia, the crystalline lens does not effectively change shape to accommodate nearby objects, and therefore people with presbyopia are unable to focus on nearby objects. Conventional lenses (e.g., eyeglass lenses and contact lenses) for correcting presbyopia include bifocal or cumulative multifocal lenses that include an area optimized for near vision and an area optimized for far vision. Presbyopia may also be treated using bifocal or cumulative multifocal lenses, or monovision lenses (wherein a different prescription is provided for each eye, with one eye provided with a distance vision lens and the other with a near vision lens).

[0005] Decades ago, it was suggested that undercorrection, i.e., moving the focus closer to the retina but not completely onto it, could be used to slow or prevent the progression of myopia in children or young people. However, the inevitable result of this approach is a loss of distance vision compared to that obtained with a lens that completely corrects myopia. Furthermore, the effectiveness of undercorrection in controlling myopia during progression is now considered questionable. A more recent approach is to provide lenses that have both areas that provide complete correction of distance vision and areas that are undercorrected or intentionally induce myopic defocus. Lenses may also be provided that increase the scattering of light in certain areas compared to light that passes through the fully corrected areas of the lens. It has been suggested that these approaches can stop or slow the progression or progression of myopia in children or young people while still providing good distance vision.

[0006] In the case of lenses with defocusing areas, the area that provides full correction of distance vision is commonly called the base power area, and the area that provides undercorrection or intentionally induces myopic defocus is commonly called the add area or myopic defocus area (because the power, expressed in diopters, is slightly more positive (+) or slightly more negative (-) than the power of the distance correction base power area). The surface of the add area (typically the anterior surface) has a smaller radius of curvature than that of the distance power area, thus providing a slightly more positive or slightly more negative power to the eye. The add area is designed to focus incoming parallel light rays (i.e., light from far away) in front of the retina (i.e., located near the lens) in the eye, while the distance power area is designed to focus light so that it can be imaged at the retina (i.e., away from the lens). When the lens wearer is using accommodation to focus light that has passed through the distance power area while viewing a near target, the add power area focuses the light in front of the retina.

[0007] For lenses that increase light scattering in certain regions, features that increase scattering may be incorporated into the lens surface or may be incorporated into the material used to form the lens. For example, scattering elements may be created in the lens surface or embedded within the lens by thermal or mechanical or light induced methods. The scattering elements may be, for example, laser induced material changes to form optical elements that are embedded in the lens material.

[0008] One known type of contact lens that reduces the progression of myopia is a bifocal contact lens marketed under the name MISIGHT (CooperVision, Inc.). This bifocal lens differs from bifocal or multifocal contact lenses designed to improve presbyopic vision in that the bifocal lens has certain optical dimensions that allow an accommodative individual to use distance correction (i.e., base power) to see both distant and near objects. The treatment zone of the bifocal lens, which has an add power, also provides a myopically defocused image at both distance and near vision distances.

[0009] Although these lenses have been found to be beneficial in preventing or slowing the progression or progression of myopia, the annular add power area may produce undesirable visual side effects. Light focused by the annular add power area in front of the retina diverges from the focal point, forming a defocused annulus at the retina. Thus, the wearer of these lenses may see a ring or "halo" surrounding the image created on the retina, especially for small shiny objects, such as street lights or car headlights. Also, in theory, instead of using the eye's natural accommodation (i.e., the eye's natural ability to change focal length) to focus on nearby objects, the wearer may utilize the additional annular add power area to focus on nearby objects, in other words, the wearer may accidentally use the lens in the same way that presbyopic corrective lenses are used, which is undesirable for young subjects.

[0010] Other lenses have been developed that can be used in the treatment of myopia. In these lenses, the annular region is configured to avoid a single on-axis image in front of the retina, which is then used to focus on a nearby target and avoid the need for accommodation. Instead, a distant point source is imaged by the annular region into a ring-like focal line at the nearby add focal plane, thereby producing a small spot size of light without a surrounding "halo" effect on the retina at the far focal plane.

[0011] It has been recognized that for treating myopia, it may be beneficial to provide a lens that introduces additional myopic defocus, and for treating presbyopia, it may be beneficial to provide a lens that produces an extended depth of focus.

[0012] It has been recognized that known lenses that include treatment portions that introduce defocus are typically designed to provide a particular treatment to the lens wearer, which can be costly and complex to design, and which can require the lens wearer to purchase different lenses that provide different degrees of correction if the lens wearer's needs change over time. Summary of the Invention [Problem to be solved by the invention]

[0013] The present invention aims to provide a simple and cost-effective alternative to known lenses used in preventing or slowing the progression of myopia. Such lenses may also be useful in correcting or improving vision associated with presbyopia, hyperopia, astigmatism, keratoconus or other refractive errors. [Means for solving the problem]

[0014] According to a first aspect, the present disclosure provides a method as set forth in claim 1.

[0015] Example embodiments will now be described, by way of example only, with reference to the accompanying schematic drawings, in which: [Brief description of the drawings]

[0016] [Figure 1] 1 is a flow diagram illustrating a method of manufacturing an ophthalmic lens, in accordance with one embodiment of the present invention. [Figure 2A] FIG. 2 is a plan view of a film including a plurality of photocured GRIN optical elements, in accordance with one embodiment of the present invention. [Figure 2B] FIG. 2B is a plan view of one of the GRIN optical elements of the lens of FIG. 2A. [Figure 2C] FIG. 2B is a perspective view of the GRIN optical element shown in FIG. 2A. [Figure 2D] FIG. 3 is a graph showing the refractive index profile of the GRIN optical element shown in FIGS. 2B and 2C. [Figure 2E] FIG. 2B is a cross-sectional view of the film of FIG. 2A applied to an ophthalmic lens. [Diagram 3] 1 is a flow diagram illustrating a method for manufacturing an ophthalmic lens using grayscale images, in accordance with one embodiment of the present invention. [Figure 4] FIG. 13 shows a grayscale image used to control light from a DLP to produce a single photocured GRIN optical element with an asymmetric refractive index distribution. [Figure 5A] 1 is a schematic diagram of a grating used to define desired locations for photocured GRIN optical elements, in accordance with one embodiment of the present invention. [Figure 5B] FIG. 13 shows a grayscale image used to control light from a DLP to produce a triangular lattice array of photocured GRIN optical elements with an asymmetric refractive index distribution. [Figure 6] FIG. 2D plot showing a modeled refractive index profile for a GRIN optical element with an asymmetric refractive index profile. [Figure 7] 4 is a flow diagram illustrating how to convert a modeled desired refractive index distribution into a light intensity map for use in a method according to one embodiment of the present invention. [Figure 8A] FIG. 2 is a plan view of a lens with a film including a plurality of photocured GRIN optical elements made using a method according to one embodiment of the present invention. [Figure 8B] FIG. 8B is a cross-sectional side view of the lens of FIG. 8A. [Figure 9] 1 is a front view of a pair of eyeglasses including lenses made according to the method of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] According to a first aspect, the present disclosure provides a method of manufacturing an ophthalmic lens. The method includes providing a lens substrate and providing a photocurable film. The method includes photocuring at least one region of the film using a digital light projection system, thereby producing at least one gradient index optical element having an asymmetric refractive index profile. The method includes applying the film to a surface of the lens substrate.

[0018] The film may be a crosslinked polymer film. The film may be a thin film. The film may be formed from a matrix of a non-crosslinked polymer. The film may be a Bayfol® HX film. The film may have a uniform thickness.

[0019] The ophthalmic lens may be a lens that prevents or slows the onset or progression of myopia. The lens may be a lens for correcting or improving vision associated with presbyopia, hyperopia, astigmatism, keratoconus, or other refractive errors.

[0020] The lens substrate may be applied to an ophthalmic lens during manufacture of the lens. Alternatively, the lens substrate may be an ophthalmic lens.

[0021] The film may cover the entire surface of the lens or substantially all of the surface of the lens. Alternatively, the film may cover a portion of the surface of the lens. The film may cover a central portion of the surface of the lens, for example, the portion that is configured to be in front of the lens wearer's eye when an ophthalmic lens is used. The film may cover an annular area of ​​the surface surrounding the center of the lens. There may be a peripheral area of ​​the lens that is not covered by the film.

[0022] The base refractive index of the film may be uniform. The base refractive index of the film may be between 1.3 and 1.8, preferably about 1.5. Each of the at least one GRIN optical element may have an average refractive index greater than the base refractive index. Alternatively, each of the at least one GRIN optical element may have an average refractive index less than the base refractive index.

[0023] The lens has an optical axis. The optical axis of the lens is defined relative to a distant point source of light. Light from a distant point source located on the optical axis of the lens (hereinafter sometimes referred to as an on-axis distant point source) is focused on the optical axis of the lens. The optical axis is preferably located along the center line of the lens. For example, if the lens is a contact lens, the optical axis is generally located along the center line of the lens. However, the optical axis may of course not be located along the center line of the lens, as is the case with spectacle lenses, where the position of the optical axis of the lens is determined by the interpupillary distance of the wearer and may not coincide with the center line of the lens depending on the shape of the lens. When the film is applied to the lens, at least one gradient index (GRIN) optical element focuses light from a distant point source on the optical axis to a point located at a first distance from the optical axis of the lens.

[0024] When the film is applied to the lens, the light from a distant point source on axis that passes through the film is focused to a focal point on the optical axis of the lens. The base power focal plane may be defined as a surface that is perpendicular to the optical axis of the lens and passes through the focal point of the lens. The term surface as used herein does not mean a physical surface, but a surface that can be drawn through a point that focuses light from a distant object. Such a surface is also called an image surface (even though it may be curved) or an image shell. The eye focuses light onto a curved retina, and in a perfectly focused eye, the curvature of the image shell matches the curvature of the retina. Thus, the eye does not focus light onto a flat mathematical plane. However, in the art, the curved surface of the retina is commonly referred to as a plane. When the film is applied to the lens, the light from a point source on axis that passes through the film is focused to a focal point on the optical axis of the lens at the base power focal plane.

[0025] In the context of the present disclosure, each of the at least one GRIN optical element is an element with a graded and asymmetric refractive index distribution in a plane parallel to the surface of the film. Each element may be substantially cylindrical or may be cylindrical with an elliptical or oval cross section, the cylindrical axis of each element being perpendicular to the plane of the layer. Each element may be substantially spheroidal or cubic. Each element may have a circular, elliptical, oval or square cross section in a plane parallel to the surface of the film. Each element may have a circular, elliptical, oval or square cross section and a flat surface coplanar with the surface of the film. In embodiments of the present invention, the change in refractive index across the at least one GRIN optical element is asymmetric in at least one lateral direction, i.e., a direction extending parallel to the surface of the layer. As a result of the asymmetric refractive index distribution, when the film is applied to a lens, light coming from a distant on-axis point source passing through at least one GRIN optical element is directed towards a point that is not located on the optical axis of the lens (i.e., an off-axis focus).

[0026] Each of the at least one GRIN optical elements is a lens with its own local optical axis. When the film is applied to the lens, the local optical axis of each of the at least one GRIN optical elements is tilted with respect to the optical axis of the lens as a result of the asymmetric refractive index distribution. The local optical axis of each of the at least one GRIN optical elements is defined with respect to a distant point source. Light from a distant point source located on the local optical axis of the GRIN optical element (hereinafter sometimes referred to as an on-axis distant point source) is focused on the local optical axis of the GRIN optical element. GRIN optical elements that exhibit an asymmetric change in refractive index in a direction parallel to the surface of the film (i.e., in the lateral direction) have a local optical axis tilted with respect to the optical axis of the lens, so that light from an on-axis distant point source passing through each GRIN optical element is focused to a point located at a first distance from the optical axis of the lens. The focusing power of each GRIN optical element is determined by the refractive index distribution of the GRIN optical element.

[0027] Any or all of the at least one GRIN optical element may be configured such that when the film is applied to the lens, light rays from an on-axis far point light passing through the GRIN optical element form a small spot of light centered on the optical axis of the lens at the base power focal plane. Thus, although each of the GRIN optical elements can focus light toward an off-axis focus, the approximate superposition of an image formed from light passing through a region of the lens with the base refractive index and a defocused image formed from light passing through the GRIN optical element can improve the quality or contrast of the image focused at the retina and can improve the vision of the lens wearer. Alternatively, any or all of the at least one GRIN optical element may be configured such that when the film is applied to the lens, light from an on-axis far point source passing through the GRIN optical element does not intersect the optical axis of the lens at the base power focal plane. This may result in a decrease in the contrast or quality of the image focused at the retina, which may be advantageous in limiting the progression of myopia.

[0028] The asymmetric variation in refractive index may be a radial variation in refractive index, i.e., the refractive index may vary radially outward from a point at the center of the GRIN optical element and extending in a plane (i.e., cross-section) parallel to the surface of the film. The asymmetric variation in refractive index may be a circumferential variation, i.e., the refractive index may vary around the circumference of the GRIN optical element in a plane parallel to the surface of the film, and the variation in refractive index may be different along different medians of the GRIN optical element.

[0029] The asymmetric change in refractive index may be in a linear direction parallel to the surface of the film.

[0030] The asymmetric variation in refractive index may be a combination of linear and radial and / or circumferential variations in the transverse cross-section.

[0031] Advantageously, the GRIN optics can provide defocus, which it is believed can help prevent or slow the progression of myopia. It is believed that the defocus can help correct or improve vision associated with presbyopia, hyperopia, astigmatism, keratoconus, or other refractive errors. The GRIN optics can be arranged such that they provide a random refractive index modulation across the film, thereby increasing the spread of light across the retina and reducing image contrast.

[0032] The change in refractive index of any of the at least one GRIN optical element may be defined by a non-symmetric polynomial function.

[0033] The film may include a plurality of GRIN optical elements. The film may include a plurality of GRIN optical elements arranged randomly distributed across an entire layer. The plurality of GRIN optical elements may be arranged randomly distributed across a portion of the film. The film may include a plurality of GRIN optical elements arranged to form at least one annular ring. The at least one annular ring may be circular, oval or elliptical in shape. The film may have a film axis extending in a direction substantially perpendicular to the plane of the film. The film may have a substantially circular cross-section and the film axis may be positioned at or near the radial midpoint of the film. At least one annular ring may be centred on the film axis. When the film is applied to the lens, the film axis may coincide with the optical axis of the lens. When the film is applied to the lens, the film may be configured such that the centre of the at least one annular ring is centred on the optical axis of the lens. The film may be arranged so that the GRIN optical elements form at least two concentric annular rings located at different radial distances from the optical axis of the lens.

[0034] If the lens is a spectacle lens, it may be advantageous to distribute the GRIN optics over a relatively large area of ​​the lens substrate, as this may maintain the defocus caused by the GRIN optics as the lens wearer's eye moves relative to the lens. Multiple GRIN optics distributed over the spectacle lens may maintain a consistent myopic defocus.

[0035] The GRIN optical elements may be positioned at regular intervals across the entire film or a portion of the film. The GRIN optical elements may be located on the grid points of a triangular lattice. The GRIN optical elements may be located on the grid points of a square or rectangular lattice.

[0036] The GRIN optical elements may be arranged to form an annular pattern on the film. When the film is applied to the lens, the film may be configured such that the annular pattern leaves a central region of the lens free of GRIN optical elements. The lens may have a central region having a diameter of up to 8 mm, the central region being free of GRIN optical elements. The annular pattern may include a single annular area or multiple concentric annular areas.

[0037] The film may include at least one second annular ring of GRIN optical elements. When the film is applied to the lens, the second annular ring of optical elements may be positioned at different radial distances from the optical axis of the lens.

[0038] At least two of the GRIN optical elements may be substantially identical, i.e., the GRIN optical elements may be of the same size and shape, and the GRIN optical elements may have the same asymmetric refractive index distribution. In this case, when the film is applied to the lens, the at least two GRIN optical elements may focus light from an on-axis, far-point source toward a point that is not on the optical axis of the lens, but is located on the same focal plane. The refractive index distribution of the at least two GRIN optical elements may be varied such that when the lens is positioned on the eye, light from an on-axis, far-point source passing through the GRIN optical element is located at a surface that is closer to the posterior surface of the lens than the base power focal plane. The refractive index distribution of the at least two GRIN optical elements may be varied such that when the lens is positioned on the eye, light from an on-axis, far-point source passing through the GRIN optical element is focused at a surface that is further from the posterior surface of the lens than the base power focal surface.

[0039] When the film is applied to the lens, substantially identical GRIN optical elements positioned at the same radial distance from the optical axis of the lens (e.g., GRIN optical elements arranged in circular concentric rings with their centers on the optical axis) can focus light toward off-axis points that are equidistant from the optical axis of the lens and that are on the same focal plane. Thus, focal points formed from light passing through these GRIN optical elements can form circular rings at the focal plane. Similarly, substantially identical GRIN optical elements can be arranged to form elliptical or oval rings with their centers on the optical axis, and focal points formed from light from an on-axis, far point source passing through these GRIN optical elements can form elliptical or oval rings at the focal plane.

[0040] At least two of the GRIN optical elements may have different asymmetric refractive index profiles, where the at least two GRIN optical elements have different local optical axes. When the film is applied to the lens, for a first and second GRIN optical elements having different refractive index profiles and positioned at the same radial distance from the optical axis of the lens, light from an on-axis far point source passing through the first GRIN optical element may be focused to a point located a first distance away from the optical axis of the lens, and light from an on-axis far point source passing through the second GRIN optical element may be focused to a point located a second, different distance away from the optical axis of the lens. The focal points of each of the GRIN optical elements are determined by the asymmetric refractive index profile of the GRIN optical element and the position of the GRIN optical element.

[0041] When the film is applied to a lens, at least two of the GRIN optical elements having different refractive index profiles can focus light towards different focal planes.

[0042] Each of the plurality of GRIN optical elements may have a different change in refractive index. Alternatively, some of the GRIN optical elements may have the same change in refractive index while others have different changes in refractive index. The plurality of GRIN optical elements may be distributed such that GRIN optical elements having the same or nearly the same change in refractive index may be grouped in a cluster or ordered array. The film may be divisible into a plurality of separate portions, each portion including GRIN optical elements having the same or nearly the same change in refractive index.

[0043] There may be a correlation between the refractive index profile of each of the at least one GRIN optical element and its radial position from the film axis and / or the optical axis of the lens when the film is applied to the lens. GRIN optical elements positioned at the same radial distance from the film axis and / or the optical axis of the lens (e.g., positioned around a circular ring whose center is located on the film axis and / or the optical axis of the lens) may have the same refractive index profile. GRIN optical elements positioned at different radial distances from the film axis and / or the optical axis of the lens may have different refractive index profiles.

[0044] A GRIN optic positioned a relatively long radial distance from the film axis and / or the optical axis of the lens may have a refractive index profile that results in a greater focusing power than a GRIN optic positioned a relatively short radial distance from the film axis and / or the optical axis of the lens. When the ophthalmic lens is in use, a GRIN optic positioned a relatively long radial distance from the optical axis of the lens can focus light from an on-axis, far point source toward a surface that is closer to the posterior surface of the lens substrate than a GRIN optic positioned a relatively short radial distance from the optical axis of the lens.

[0045] The film may include GRIN optical elements forming a first circular ring, the GRIN optical elements may have a first refractive index profile. The film may include GRIN optical elements forming a second circular ring, the GRIN optical elements may have a second, different refractive index profile. The first circular ring may be located at a shorter radial distance from the optical axis of the lens and / or the axis of the film than the second circular ring. When the film is applied to the lens, as a result of the first refractive index profile, the GRIN optical elements may be part of a first ring that focuses light towards a first focal plane, and as a result of the second refractive index profile, the GRIN optical elements may be part of a second ring that focuses light towards a second focal plane. When the lens is worn by a user, the first focal plane and / or the second focal plane may be closer to the rear surface of the lens than the base focal plane. The first focal plane may be located closer to the rear surface of the lens than the second focal plane.The first focal plane may be located farther from the rear surface of the lens than the second focal plane.

[0046] The film may include GRIN optical elements forming a number of concentric annular rings. The GRIN optical elements within the same annular ring may have the same refractive index distribution. The GRIN optical elements forming the different annular rings may have different refractive index distributions. The annular rings positioned at a relatively long radial distance from the optical axis of the lens and / or the film axis may include GRIN optical elements having a change in refractive index resulting in a large focusing power of the optical element. When the lens is in use, the annular rings positioned at a relatively long radial distance from the optical axis of the lens substrate may consist of GRIN optical elements that focus light towards a surface located closer to the rear surface of the lens than the annular rings positioned at a relatively short radial distance from the optical axis of the lens. Alternatively, the annular rings positioned at a relatively long radial distance from the optical axis of the lens and / or the film axis may include GRIN optical elements having a small focusing power. When an ophthalmic lens constituting such a lens is in use, annular rings positioned at a relatively large radial distance from the optical axis of the lens may comprise GRIN optical elements that focus light toward a surface located further from the posterior surface of the lens than annular rings positioned at a relatively small radial distance from the optical axis of the lens.

[0047] Each of the at least one GRIN optical element can cause additional scattering of light incident on the GRIN optical element as compared to light incident on the remainder of the film.

[0048] Each of the at least one GRIN optical elements may have a minimum difference in refractive index compared to the base refractive index of at least 0.001, preferably at least 0.005. Each of the at least one GRIN optical elements may have a minimum refractive index 0.001 greater than the base refractive index. Each of the at least one GRIN optical elements may have a minimum refractive index 0.005 greater than the base refractive index. Each of the at least one GRIN optical elements may have a maximum refractive index 0.005 less than the base refractive index. Each of the at least one GRIN optical elements may have a maximum refractive index 0.001 less than the base refractive index. Each of the at least one GRIN optical elements may have a maximum difference in refractive index compared to the base refractive index of less than 0.1, preferably less than 0.025. Each of the at least one GRIN optical elements may have a maximum refractive index 0.1 greater than the base refractive index. Each of the at least one GRIN optical elements may have a maximum refractive index 0.025 greater than the base refractive index. Each of the at least one GRIN optical elements may have a minimum refractive index of 0.1 less than the base refractive index. Each of the at least one GRIN optical elements may have a minimum refractive index of 0.025 less than the base refractive index. Each of the at least one GRIN optical elements may have a minimum refractive index equal to the base refractive index. Each of the at least one GRIN optical elements may have a minimum refractive index of -25D to +25D, preferably -0.25D to +25.0D. For lenses used in preventing or slowing the progression or worsening of myopia, each GRIN optical element may have a minimum refractive index of -0.25 to +25.0D. For lenses used in preventing or slowing the progression or worsening of hyperopia, each GRIN optical element may have a minimum refractive index of 0.0 to -25.0D.

[0049] The film may have a finite thickness and each of the at least one GRIN optical elements may extend through the thickness of the film. Each of the at least one GRIN optical element may only partially penetrate the thickness of the film. Each of the at least one GRIN optical element may be embedded within the film. The thickness of the film may be uniform. Each of the at least one GRIN optical element may be embedded within the film without adding a change to the thickness of the film. Each of the at least one GRIN optical element may have a uniform thickness. Each of the at least one GRIN optical element may have a flat surface that lies flush with a surface of the film.

[0050] The film may be a cross-linked polymer film including at least one GRIN optical element. The film may be made of a matrix of a non-cross-linked polymer. The film may be bonded to the lens substrate. The film may be bonded to the lens substrate using a plasma. The film may be glued to the lens substrate. The film may be glued to the lens substrate using a curable adhesive.

[0051] The film may be provided on the lens substrate and / or the anterior surface of the lens. The film may be provided on the lens substrate and / or the posterior surface of the lens. The film may be provided on both the anterior and posterior surfaces of the lens substrate and / or the lens. The film may comprise Bayfol® HX film. The film may be removably attached or otherwise applied to the lens substrate, i.e., the film may be easily removed from the lens substrate. The film may be reusable, such that the film may be easily removed and reapplied to the same substrate or a different lens substrate.

[0052] The film should have a uniform thickness.

[0053] The film should be a flexible, transparent film. In the case of contact lenses, the film should have a thickness of 1 μm to 100 μm, preferably 10 μm to 20 μm, and more preferably 14 μm to 18 μm. In the case of spectacle lenses, the film should have a thickness of 1 μm to 1000 μm, preferably 10 μm to 20 μm, and more preferably 14 μm to 18 μm.

[0054] The lens substrate may be attached to the ophthalmic lens during manufacture of the lens. The lens substrate may be removably attached or otherwise attached to the ophthalmic lens, i.e., the lens substrate may be easily removed from the ophthalmic lens. The lens substrate may be reusable, such that the lens substrate may be easily removed and reattached to the same lens substrate or to a different lens substrate. Alternatively, the lens substrate may be an ophthalmic lens.

[0055] The ophthalmic lens may be a spectacle lens. The spectacle lens may be made of PMMA, CR-39, polycarbonate, Trivex®, or crown glass. The ophthalmic lens may be a contact lens. The film may be provided on the anterior surface of the ophthalmic lens. In the context of this disclosure, the anterior surface of the ophthalmic lens is the front-facing or outer surface of the lens when the ophthalmic lens is worn by a lens wearer.

[0056] The ophthalmic lens may be circular in shape. The ophthalmic lens may be elliptical in shape. The ophthalmic lens may be oval in shape. The ophthalmic lens may be rectangular in shape. The ophthalmic lens may be square in shape. The anterior surface of the ophthalmic lens may be 1200 mm 2 ~3000mm 2The ophthalmic lens may have an area of ​​0.1 mm to 0.5 mm. The ophthalmic lens may be made of clear glass or hard plastic, such as polycarbonate. The ophthalmic lens may be substantially flat and may have at least one curved surface that provides the lens power.

[0057] The ophthalmic lens may be a contact lens. As used herein, the term contact lens refers to an ophthalmic lens that can be placed on the anterior surface of the eye. It will be understood that such contact lenses provide clinically acceptable on-ocular movement and do not adhere to one or both of a person's eyes. The contact lens may be in the form of a corneal lens (e.g., a lens that remains seated on the cornea of ​​the eye). In embodiments where the lens is a contact lens, the lens may be in the form of a corneal lens having a diameter of 60 mm or less. 2 ~750mm 2 The lens may have a surface area of ​​0.1 mm to 0.5 mm. The lens may be circular in shape. The lens may be oval in shape. The lens may be elliptical in shape. The lens may have a diameter of 10 mm to 15 mm.

[0058] The lens may be a rigid (hard) contact lens. The lens may be a gas permeable hard contact lens.

[0059] The contact lens may be a toric contact lens, for example a toric contact lens may have an optical zone configured to correct a person's astigmatism. The lens may be a scleral contact lens.

[0060] Ophthalmic lenses may be soft contact lenses, such as hydrogel contact lenses or silicone hydrogel contact lenses.

[0061] The ophthalmic lens may be made of an elastomeric material, a silicone elastomer material, a hydrogel material, or a silicone hydrogel material, or a mixture thereof. As understood in the contact lens field, a hydrogel is a material that retains water at equilibrium and is free of silicone-containing chemicals. A silicone hydrogel is a hydrogel that includes silicone-containing chemicals. The hydrogel and silicone hydrogel materials described in the context of the present invention have an equilibrium water content (EWC) of at least 10% to about 90% (w / w). In some embodiments, the EWC of the hydrogel or silicone hydrogel material is about 30% to about 70% (w / w). To illustrate a comparative example, the silicone elastomer materials described in the context of the present invention have a water content of about 0% to less than 10% (w / w). Typically, the silicone elastomer materials used in the methods or devices of the present invention have a water content of 0.1% to 3% (w / w). Examples of suitable lens formulations include those having the following United States Adequate Names (USAN): methafilcon A, ocufilcon A, ocufilcon B, ocufilcon C, ocufilcon D, omafilcon A, omafilcon B, comfilcon A, enfilcon A, stenfilcon A, fanfilcon A, etafilcon A, ) A, senofilcon A, senofilcon B, senofilcon C, narafilcon A, narafilcon B, balafilcon A, samfilcon A, lotrafilcon A, lotrafilcon B, somofilcon A, riofilcon A, delefilcon A, verofilcon A, kalifilcon A, and the like.

[0062] Alternatively, each lens may comprise, consist essentially of, or consist of a silicone elastomer material. For example, the lenses may comprise, consist essentially of, or consist of a silicone elastomer material having a Shore A hardness of 3 to 50. The Shore A hardness can be determined using conventional methods (e.g., using method DIN 53505), as will be appreciated by those skilled in the art. Other silicone elastomer materials can be obtained, for example, from NuSil Technology or Dow Chemical Company.

[0063] An ophthalmic lens may have an optical zone. The optical zone surrounds the portion of the lens with an optical function. The optical zone is configured to be positioned over or in front of the pupil of the eye in use. The optical zone may be surrounded by a peripheral zone. The peripheral zone is not part of the optical zone, but is located outside the optical zone. In a contact lens, the peripheral zone may be located over the iris when the lens is worn. The peripheral zone may perform a mechanical function, for example, increasing the size of the lens to make it easier to handle. In a contact lens, the peripheral zone may provide a ballast stabilization effect to prevent rotation of the lens and / or provide an irregular region that increases comfort for the lens wearer. The peripheral zone may extend to the edge of the contact lens. In embodiments of the present invention, when a film is applied to the lens substrate, the film may cover the optical zone, but it may not cover the peripheral zone.

[0064] Each of the at least one GRIN optical elements has a width of 1 μm to 5 mm, preferably 10 μm to 2 mm. 3 ~5mm 3 , preferably 10 μm 3 ~2mm 3The plurality of GRIN optical elements may occupy between 5% and 80% of the volume of the film. The plurality of GRIN optical elements may cover between 20% and 80% of the surface area of ​​the film. The film may include between 2 and 5000 GRIN optical elements.

[0065] The lens may have a central region and an annular region surrounding the central region. When the film is applied to the lens, it may cover a portion of the annular region. The film may not cover the central region, and therefore may be devoid of GRIN optical elements. The film may cover all of the annular region or a portion of the annular region. The term annular region as used herein refers to a region that may extend over the entire outer edge of the central region or may extend partially along the outer edge of the central region. The annular region may be circular, oval, or elliptical in shape. The annular region may include a plurality of GRIN optical elements. The plurality of GRIN optical elements may be distributed around the entire annular region or may be distributed over a portion of the annular region.

[0066] The film may include a plurality of concentric annular regions radially separated by regions of the film having the base refractive index.

[0067] The lens may further comprise an adhesive disposed between the film and the surface of the lens substrate. The adhesive may consist of a transparent adhesive, for example an epoxy adhesive. The adhesive may be an adhesive layer. The adhesive layer may be applied to the front surface of the lens substrate during manufacture of the lens. The adhesive may permanently adhere the layer to the surface of the lens substrate. Alternatively, the film may be bonded to the surface of the lens substrate. The film may be permanently bonded to the surface of the substrate or may be irreversibly bonded.

[0068] The lens may further include a protective layer disposed on the front surface of the film. The front surface of the film containing at least one GRIN optical element is the forward facing or outer surface of the film when the lens is in normal use and worn by the lens wearer. The protective layer may cover all or a portion of the front surface of the film. The protective layer may be a transparent layer. The protective layer may be comprised of polycarbonate (PC). The protective layer may be comprised of polyethylene terephthalate (PET) or cellulose triacetate (TAC). The protective layer may be comprised of a material having negligible birefringence. The protective layer may be impermeable to water. The protective layer may be scratch resistant. The protective layer may have a base refractive index. The protective layer may provide some UV protection. The protective layer may be attached to the film using an adhesive.

[0069] In the context of this disclosure, a photocured GRIN optical element is a GRIN optical element formed by photocuring or photopolymerization. The photocured GRIN optical element may be made of photopolymerizable or photocurable molecules or other photocurable elements. The photocuring results in an asymmetric graded refractive index across the photocured area. The photocurable molecules may be dispersed within a film. The photocurable molecules may be dispersed within a crosslinked polymer matrix or within a resin.

[0070] Each of the at least one GRIN optical elements may have a refractive index profile that is asymmetric in a plane or direction parallel to the surface of the film. The asymmetric refractive index profile may be defined by an asymmetric polynomial function. Each of the at least one GRIN optical elements may have an asymmetric refractive index profile that varies in a radial direction, in a plane parallel to the surface of the film. Each of the at least one GRIN optical elements may have an asymmetric refractive index profile that varies in at least one linear direction parallel to the surface of the film. Each of the at least one GRIN optical elements may have an asymmetric refractive index profile that varies in a circumferential direction, in a plane parallel to the surface of the film.

[0071] In the context of this disclosure, a digital light projection (DLP) system is a light projection system used to direct light towards a photocurable film, thereby photocuring an area of ​​the film. The DLP system used has a wavelength suitable for photopolymerization or photocuring of the target film material. For example, for Bayfol® HX film, the DLP system may have a wavelength in the range of 440 nm to 660 nm. The pixel resolution of the DLP system may be less than 100 μm, preferably less than 30 μm, more preferably less than 10 μm. The DLP system may be a commercial DLP system, for example, the 3DLP9000-LED.9" WQXGA light engine with a wavelength of 460 nm and a pixel resolution of 30 nm. The DLP system may include a microelectromechanical system (MEMS). The DLP system may include a digital mirror device that can direct light and / or control the transmission of light towards the film.

[0072] DLP systems can be used to irradiate the entire film or a region of the film. DLP systems can be used to photocure individual photocurable elements or molecules, or multiple individual photocurable molecules. Multiple individual photocurable molecules can be photocured sequentially or simultaneously. DLP systems can be used to irradiate annular regions of the film, or multiple concentric annular regions of the film.

[0073] When a digital light projection system is used, a grayscale image may be used to control the projection of light onto the film. The grayscale image may be a template for projecting light from the DLP system onto the film. The grayscale image may be a ".bmp" (with a .bmp (bitmap) extension) image. The grayscale image may mask some areas of the film so that these areas are not exposed to light from the DLP system while at least one area of ​​the film may be exposed to light from the DLP system. The grayscale image may expose multiple areas to light from the DLP system. The areas of the film exposed to light from the DLP system may be photocured to produce photocured GRIN optical elements.

[0074] A method for manufacturing a lens can include generating a design for a film, the design having a desired pattern of photocured GRIN optical elements having an asymmetric refractive index distribution. The method can include generating a grayscale image using the design.

[0075] The grayscale image may be designed to produce any of the configurations of the photocured GRIN optical elements described above, where the GRIN optical elements have an asymmetric refractive index distribution. The grayscale image may have a number of apertures that allow light from the DLP system to reach the film. Areas of the film illuminated by the light from the DLP system may be photocured. Such an image may have a number of portions that block or mask light from reaching the film. Areas of the film not illuminated by the light from the DLP system are not photocured. Such an image may have a number of apertures arranged in a pattern. The desired pattern of photocured GRIN optical elements may be an array of GRIN optical elements arranged on grid points of the film, where the image may have a number of apertures arranged on the grid points. The grid may be a triangular grid, a square grid, or a cubic grid. Alternatively, the desired pattern of light-cured gradient index optical elements may include at least one annular ring of light-cured gradient index optical elements. The desired pattern of light-cured gradient index optical elements may include a plurality of concentric annular rings of light-cured gradient index optical elements.

[0076] The method may include modeling a desired asymmetric refractive index profile for each of at least one light-cured GRIN optical element and determining at least one light exposure condition required to produce the desired asymmetric refractive index profile.

[0077] Modeling may be used to determine the light exposure intensity and / or light exposure duration and / or light exposure wavelength required to photocure a GRIN optical element having a desired asymmetric refractive index distribution. These conditions may depend on the characteristics of the DLP system, such as the wavelength, intensity and type of light source. Such conditions may depend on the characteristics of the film, such as the film material and film thickness. Modeling may be performed using any suitable modeling software, such as MATLAB. Modeling may be performed using experimental (measured) data or theoretical (predicted) data. The predicted data may be based on known characteristics of the film material and / or the DLP system. The desired refractive index distribution of each of the photocured GRIN optical elements may be defined by or approximated by an asymmetric polynomial function. The desired asymmetric refractive index distribution may be modeled for a single photocured GRIN optical element or may be modeled for multiple photocured GRIN optical elements. For a film including multiple GRIN optical elements, the desired asymmetric refractive index profile of each of the at least one photocured GRIN optical element may be the same, or each of the photocured GRIN optical elements may have a different desired asymmetric refractive index profile.

[0078] The modeling step may include measuring or plotting a desired refractive index change map as a function of light exposure conditions. The light exposure conditions may be light intensity, exposure duration, or light wavelength. The map may be generated as a map having a non-flat surface. The map may be generated as a 3D map. The map may be iteratively updated and / or optimized to produce a desired refractive index distribution of the photocured GRIN optical element. The map may be a refractive index change map for a single photocured GRIN optical element, or may be a refractive index change map for multiple photocured GRIN optical elements. The map may be used to produce a refractive index gradient pixel matrix for use in a DLP imaging system. The pixel matrix may specify desired light exposure conditions for each pixel of the DLP imaging system to produce a desired refractive index change across the film. The refractive index gradient pixel matrix may be configured to produce a single photocured GRIN optical element, or may be configured to produce 2-5000 photocured GRIN optical elements distributed across the film. The gradient index pixel matrix may be configured to produce photocured GRIN optical elements over 20% to 80% of the area of ​​the film.

[0079] The modeling step may include converting the refractive index variation map into a digital light projection intensity map. The digital light projection intensity map may be a pixel matrix for the DLP system. The digital light projection intensity map may be generated from the refractive index gradient pixel matrix. The digital light projection intensity map may be used to generate a grayscale image for use with the DLP system. The digital light projection intensity map may be used to determine required illumination conditions for use with the DLP system. The DLP intensity map may be used to generate a ".bmp" image. The image may be an 8-bit image. The light exposure conditions may depend on the type of film, the desired pattern or arrangement of the photocured GRIN optical elements, the film characteristics, and the DLP imaging system characteristics. The digital light projection intensity map may then be used to control the projection of light onto the film by determining the required illumination conditions.

[0080] As a result of the modeled desired refractive index distribution, an asymmetric refractive index distribution can be obtained when the refractive index variation map is converted into a digital light projection intensity map.

[0081] The desired refractive index profile can result in an asymmetric refractive index profile that varies radially in a plane parallel to the surface of the film. The desired refractive index profile can result in an asymmetric refractive index profile that varies in at least one linear direction parallel to the surface of the film. The desired refractive index profile can result in an asymmetric refractive index profile that varies circumferentially in a plane parallel to the surface of the film.

[0082] The modeling step may include modeling at least two different desired refractive index profiles for at least two different photocured GRIN optical elements. The modeling step may include selecting a desired refractive index profile for each of the at least one GRIN optical element depending on the position of the optical element within the desired pattern. If the desired pattern of GRIN optical elements includes multiple concentric annular rings of photocured gradient index optical elements, the modeling step may include selecting the same desired refractive index profile for GRIN optical elements forming the same annular ring. The modeling step may include selecting different desired refractive index profiles for GRIN optical elements that are part of different annular rings. The modeling step may include selecting a desired refractive index for each of the at least one GRIN optical element such that GRIN optical elements positioned at the same radial distance from the film axis have the same desired refractive index profile. The modeling step may include selecting a desired refractive index profile for each of the at least one GRIN optical element such that GRIN optical elements positioned at a relatively large distance from the film axis have a more asymmetric desired refractive index profile. Alternatively, the modeling step may include selecting a desired refractive index profile for each of the at least one GRIN optical element such that GRIN optical elements positioned at a relatively large distance from the film axis have a more symmetric desired refractive index profile.

[0083] The method may include exposing the film to light from a DLP while using a grayscale image and / or a digital light projection intensity map to control the projection of light across the film onto the light exposure. The method may include waiting for a minimum development time for the film. After waiting for the minimum development time for the film, the method may include flood curing or flood exposing the film using a DLP system or a UV oven.

[0084] The DLP system may include optical components that produce a non-linear intensity response. The method may include determining whether there is a significant non-linear response for any pixel or across pixels. If there is a significant non-linear response, the method may include applying a digital light projection intensity map to take the non-linear response into account.

[0085] The desired refractive index profile for each of the at least one GRIN optical element may result in a photocured GRIN optical element having a diameter between about 1 μm and 5.0 mm. The modeled refractive index profile may be configured to result in the at least one photocured GRIN optical element having a diameter between about 1 μm and 5.0 mm. The modeled refractive index profile may be optimized or iteratively optimized to result in the at least one photocured GRIN optical element having a diameter between about 1 μm and 5.0 mm. The desired refractive index profile for each of the at least one photocured GRIN optical element may result in a deposition of 1 μm. 3 ~5mm 3 The desired refractive index profile for each of the at least one photo-cured GRIN optical element may result in a disk-shaped photo-cured GRIN optical element or a spherical photo-cured GRIN optical element having an asymmetric profile in a direction parallel to the surface of the film. The modeled refractive index profile may be optimized or iteratively optimized to produce at least one photo-cured GRIN optical element having any of the characteristics described above.

[0086] The method may include applying the film to the surface of the lens or lens substrate after photocuring. The film may be provided on a second substrate for photocuring and then removed from the second substrate and applied to the lens or lens substrate. The second substrate may be a glass slide. The film may be applied to the surface of the lens prior to photocuring. The film may be attached to the surface of the lens using an adhesive, for example an epoxy adhesive. The adhesive may be an adhesive layer. The adhesive layer may be applied to the front surface of the lens during manufacture of the lens. The adhesive layer may be applied to the rear surface of the film prior to application of the film to the lens surface. The adhesive may permanently attach the film to the surface of the lens. The adhesive may releasably attach the film to the surface of the lens.

[0087] Prior to application of the film to a lens or lens substrate, which may be before or after photocuring a region of the film, the film may be cut or shaped to be suitable for application to an ophthalmic lens. The film may be cut or shaped to cover the entire surface of the lens or a portion of the surface of the lens. The film may be cut or shaped to be circular, oval, or elliptical. The film may be cut or shaped to cover the optical zone of the lens, or the area of ​​the lens that is located in front of the lens wearer's retina when the lens wearer wears the lens.

[0088] A protective layer may be applied to the surface of the film prior to photocuring. The method may include the step of removing the protective layer prior to photocuring. The protective layer may be comprised of polypropylene.

[0089] After applying the photocured film to the lens, the method may include applying a protective layer to the front surface of the lens (i.e., over the photocured layer). The protective layer may cover all or a portion of the front surface of the film containing the at least one photocured GRIN optical element. The protective layer may be a transparent layer. The protective layer may be made of polycarbonate (PC). The protective layer may be made of polyethylene terephthalate (PET) or cellulose triacetate (TAC). The protective layer may be made of a material having negligible birefringence. The protective layer may be impermeable to water. The protective layer may be scratch resistant. The protective layer may have a base refractive index. The protective layer may provide some UV protection. The protective layer may be attached to the film containing the at least one photocured GRIN optical element using an adhesive.

[0090] FIG. 1 is a flow diagram illustrating a method 100 for manufacturing an ophthalmic lens, according to one embodiment of the present invention. In a first step 103, an ophthalmic lens is provided, and in a second step 105, a photocurable film is provided. In a third step 107, a digital light projection system (DLP) is used to create at least one photocured GRIN optical element with an asymmetric refractive index distribution in the photocurable film. The DLP system directs light toward the photocured film to illuminate an area of ​​the film, thereby creating at least one photocured GRIN optical element with an asymmetric refractive index distribution. In a fourth step 109, the film is applied to a surface of a lens substrate.

[0091] FIG. 2A is a schematic plan view of a film 1 that can be applied to an ophthalmic lens, including a plurality of photocured GRIN optics 7a, 7b, made using a method according to an embodiment of the present invention. The GRIN optics 7a, 7b are arranged in concentric circles 9a, 9b (the dashed lines 9a, 9b are provided as guides for the eye and do not represent structural features of the film 1). The centers of the concentric circles lie on the film axis 3, which extends in a direction that is substantially perpendicular to the plane of the film 1. FIG. 2B is a plan view of one of the GRIN optics 7a of the film 1 shown in FIG. 2A, and FIG. 2C shows the same optic 7a in a perspective view. Each of the GRIN optics 7a, 7b is substantially cylindrical in shape with an elliptical cross section when viewed in a plane parallel to the surface of the film 1. Each of the GRIN optical elements 7a, 7b has a refractive index distribution that varies both radially and laterally in a plane perpendicular to the cylindrical axis of the optical element 7a, 7b, i.e., in a plane parallel to the surface of the film 1, resulting in an asymmetric refractive index distribution across the optical element 7a, 7b. The refractive index in a direction perpendicular to the cylindrical axis of the optical element 7a and across the surface of the optical element 7a, 7b varies radially outward from a point "X" in a plane parallel to the front surface of the film 1 and in a direction indicated by an arrow "Y" parallel to the front surface of the film 1. The refractive index distribution is constant (i.e., does not vary) in a direction "Z" (see FIG. 2C) parallel to the cylindrical axis of the optical element 7a, 7b. The change in refractive index exhibits an asymmetric distribution 22 in the direction "Y" as shown in FIG. 2D.

[0092] The GRIN optics 7a forming the inner circle 9a all have the same refractive index profile (as shown in Figures 2B and 2C) and are all located at the same radial distance from the film axis 3. Figure 2E is a cross-sectional view of the film axis 1 of Figure 2A as applied to a lens substrate 5 (in this case, the lens substrate 5 is an ophthalmic lens 5). The film axis 3 is aligned with the optical axis 2 of the lens 5. Because the GRIN optics 7a have an asymmetric refractive index profile, when the film 1 is applied to the lens 5, the local optical axis of the GRIN optics 7a will be tilted with respect to the optical axis 2 of the lens 5. Light from a distant point source on the optical axis 2 of the lens 5 (hereafter referred to as an on-axis distant point source) that passes through a region of the film 1 having the base refractive index is focused to a spot 11 on the optical axis 2. Light from an on-axis distant point source that passes through the GRIN optics 7a is focused away from the light source 2 of the lens 5. Light from an on-axis distant point source passing through the GRIN optics 7a forming the inner ring 9a will form a ring of focal points 15a, 15b at the focal plane 17. When the lens 5 is worn by the lens wearer, the GRIN optics 7a forming the inner ring 9a focus the light from the on-axis distant point source toward the add focal plane 17 located closer to the posterior surface of the lens 5 (i.e., away from the retina or closer to the cornea) compared to the base power focal plane. The local optical axis of each of the GRIN optics 7a intersects with the optical axis of the lens, and the light rays from the on-axis distant point source passing through the GRIN optics 7a forming the inner ring 9a are directed such that a small spot size of unfocused light is produced at the base power surface 13. This can improve the quality of the image produced at the lens wearer's retina.

[0093] All of the GRIN optical elements 7b forming the outer ring 9a exhibit the same refractive index change as the GRIN optical elements 7a forming the inner ring 9a (as shown in Figures 2A and 2E). All of the GRIN optical elements 7b forming the outer ring 9a are positioned at the same radial distance from the optical axis 2 and film axis 3 of the lens 5, and at a greater distance from the optical axis 2 and film axis 3 than the GRIN optical elements 7a forming the inner ring 9a.

[0094] The GRIN optical elements 7b are arranged in a circle located on the optical axis 2 of the lens 5, the center of which is coincident with the film axis 3. The GRIN optical elements have local optical axes that focus light from an on-axis distant point source that passes through the GRIN optical elements 7b to form rings of foci 19a, 19b (shown in FIG. 2E). The rings of foci 19a, 19b have a larger radius than the rings of foci 15a, 15b formed from light that passes through the inner ring 9a of the GRIN optical element 7a. The refractive index profile of the GRIN optical elements 7b forming the outer ring 9b is identical to the refractive index profile of the GRIN optical elements 7b forming the inner ring 9a. When the lens 5 is worn by a wearer, the GRIN optical elements 7b forming the outer ring 9b focus light toward the same add focal plane 17 as the GRIN optical elements 7a forming the inner ring 9a. The local optical axis of each of the GRIN optics 7b intersects with the optical axis 2 of the lens 4 and the film axis 3, and light rays from an on-axis distant point source passing through the GRIN optics 7b forming the outer ring 9b are directed such that a small spot size of unfocused light is formed at the base power surface 13. This can improve the quality of the image produced at the lens wearer's retina.

[0095] FIG. 3 is a flow diagram illustrating a method 1300 of manufacturing an ophthalmic lens using a grayscale according to an embodiment of the present invention. In a first step 1301, a design of a film is created that includes a pattern of GRIN optical elements with an asymmetric refractive index distribution. The design includes the desired pattern of GRIN optical elements. In a second step 1302, the pattern is used to generate a grayscale image. In a third step 1303, the desired asymmetric refractive index distribution is modeled for each GRIN optical element. In a fourth step, an ophthalmic lens is prepared (1304), and in a fifth step, a photocurable film is prepared (1305). The grayscale image is used to provide a template for projecting light from a digital light projection system onto the film. The grayscale image masks some areas of the film so that they are not exposed to light, while other areas are exposed to light. The areas of the film exposed to the light from the DLP system are photocured to create the GRIN optical elements with an asymmetric refractive index distribution. Thus, in the sixth step, at least one photohardened GRIN optical element is created in the photohardenable film using the DLP system and the grayscale image. In the final step 1309, the film is applied to the surface of the lens substrate.

[0096] 4 shows a grayscale image 411 that can be used in a method according to one embodiment of the present invention. Dark areas 413 in the grayscale image 411 refer to areas that are not exposed to light. Light areas 415 in the grayscale image 411 refer to areas that transmit light. The areas of the film that are exposed to light are photocured to produce photocured GRIN optical elements.

[0097] 5A is a schematic diagram 517 of a grid used to define desired locations for photocured GRIN optics in methods according to embodiments of the present invention. The grid has a triangular grid pattern. Each grid point 510 defines a location where a GRIN optic will be created on the photocurable film. The grid pattern is used to create a grayscale image 511 that includes lighter areas 515 on each grid point, designated areas that allow light to pass through, and darker areas 513 that are not exposed to light, as shown in FIG. 5B.

[0098] 6 shows a two-dimensional slice 612 taken through a cross section of a modeled refractive index profile for a GRIN optical element with an asymmetric refractive index profile, which has a graded refractive index defined by an asymmetric polynomial function in three dimensions (a two-dimensional slice is shown in FIG. 6 for ease of illustration).

[0099] FIG. 7 is a flow diagram 700 showing the steps of converting a modeled desired refractive index distribution into a light intensity map for use in a method according to an embodiment of the present invention. The flow diagram starts with a graph 712 of a modeled refractive index distribution for a GRIN optical element similar to the distribution shown in FIG. 6. A plot 719 of refractive index change vs. intensity response is used to characterize the light exposure required to produce a particular refractive index change for a particular film and DLP system. This plot 719 and the modeled refractive index distribution can be used to create a digital light projection intensity map 721, which is a pixel matrix for a DLP system. In FIG. 7a, a 2D slice is shown taken through this intensity map 721. This is used to create a grayscale image 711, which contains the desired exposure conditions used in the DLP system. The grayscale image 711 is then used to expose a photocurable film to light from the DLP, thereby controlling the light exposure pattern the film experiences. A photocured GRIN optical element with an asymmetric refractive index distribution is created on the surface of the film.

[0100] FIG. 8A is a plan view of an ophthalmic lens 205 prepared using a method according to an embodiment of the present invention. FIG. 8B is a cross-sectional side view of the lens 205 shown in FIG. 8A. A film 201 having a base refractive index is attached to the front surface of the lens 205 by an adhesive. The film 201 spans a central region of the lens 205. The central region of the lens 201 is surrounded by a peripheral region 204. The film 201 includes a plurality of GRIN optical elements 207 that are photocured using a method according to an embodiment of the present invention. The GRIN optical elements 207 are randomly distributed across the surface of the film 201 and extend through the thickness of the film 201. Each of the GRIN optical elements 207 has a gradient of refractive index that varies circumferentially around the optical element and radially outward from the center of the element in a plane perpendicular to the optical axis 202 of the lens 205. Each optical element 207 exhibits the same change in refractive index. The base index of refraction of film 201 is constant and film 201 has a uniform thickness.

[0101] 9 is a plan view of a pair of glasses 325 manufactured according to the method of the present invention. The pair of glasses 325 contains two lenses 305. Each lens 305 is centered on an optical axis 302 and has a film 301 applied to its front surface. The base index of refraction of the film 301 is uniform and the film 301 has a uniform thickness. The film 301 covers the front surface of the lens 305. Light from an on-axis distant point source that passes through the film 301 is focused to a spot on the optical axis 302 of the lens 305 at the base power focal plane (not shown).

[0102] The films 301 are arranged in concentric circles 309a, 309b (the dashed lines 309a, 309b are provided as guides for the eye and do not represent structural features of the film 1). Each of the GRIN optical elements 307a, 307b has a refractive index distribution that varies both radially and laterally across the optical elements 307a, 307b parallel to the plane of the film 301, resulting in an asymmetric distribution. All of the GRIN optical elements 307a forming the inner circle 309a exhibit the same variation in refractive index and are all positioned at the same radial distance from the optical axis 302 of the lens 305. Because the GRIN optical elements 307a have an asymmetric refractive index distribution, light from an on-axis, far-point source passing through the GRIN optical elements 307a will be focused away from the optical axis 302. The GRIN optical elements 307a are arranged in a circle with its center located on the optical axis 302 of each lens 301, so that light from an on-axis distant point source passing through the GRIN optical elements 307a forming the inner ring 309a forms a ring of focal points.

[0103] The GRIN optical elements 307b forming the outer ring 309b also all exhibit the same change in refractive index, but they exhibit a different refractive index change than the GRIN optical elements 307a forming the inner ring 309b. The GRIN optical elements 307b forming the outer ring 309b are all positioned at the same radial distance from the optical axis 302 of the lens, and at a greater distance from the optical axis 302 than the GRIN optical elements 307a forming the inner ring 309a. Light from an on-axis distant point source passing through the GRIN optical elements 307b forming the outer ring 309b forms a focal ring. This focal ring has a larger radius than the focal ring produced by light passing through the inner ring 309a of the GRIN optical element 307a. The refractive index profile of the GRIN optical elements 307b forming the outer ring 309b is different from the refractive index profile of the GRIN optical elements 307a forming the inner ring 309a. When the lens 305 is worn by a wearer, light passing through the GRIN optics 307a forming the inner ring 309a is focused to a point on a first focal plane, and light passing through the GRIN optics 307b forming the outer ring 309b is focused to a point on a different second focal plane. When the lens 305 is worn by a lens wearer, both the first and second focal planes are located closer to the posterior surface of the lens 305 than the base power focal plane.

[0104] While the present invention has been described and illustrated with reference to specific embodiments, those skilled in the art will recognize that the invention can be embodied in many different variations not specifically described herein, and only certain possible variations are described below, by way of example only.

[0105] In the exemplary embodiments of the present invention described above, each GRIN optical element has a refractive index profile that results in a focal power that is higher than the base refractive index of the lens. In other exemplary embodiments, the GRIN optical element may have a refractive index profile that results in a focal power that is lower than the base refractive index of the lens.

[0106] In the exemplary embodiments described above, the film is applied to a surface of the lens (i.e., the lens substrate forms part of the lens or is the lens itself). In other embodiments, the layer may be applied to the substrate, and then the substrate may be applied to the surface of the lens.

[0107] In the above description, reference is made to integers or elements having known obvious or foreseeable equivalents, and such equivalents are hereby set forth as if they were individually set forth. Reference should be made to the claims which define the true scope of the invention, which should be deemed to include any such equivalents. The reader will also appreciate that any integers or features of the present disclosure described as advantageous, convenient, etc. are optional and do not limit the scope of the independent claims. It should further be understood that, while considered beneficial in some embodiments of the invention, such optional integers or features may not be desirable and therefore may not be recited in other embodiments.

Claims

1. 1. A method for producing an ophthalmic lens, comprising: Providing a lens substrate; Providing a photocurable film; photocuring at least one region of the film using a digital light projection system, thereby producing at least one photocured optical element having an asymmetric refractive index profile; and applying the film to a surface of the lens substrate.

2. The method of claim 1 , wherein using the digital light projection system further comprises using a grayscale image to control the projection of light from the digital light projection system onto the film.

3. The method comprises: creating a design for the film, the design including a desired pattern of photocured gradient index optical elements; The method of claim 2 further comprising the step of forming said grayscale image using said design.

4. The method of claim 3 , wherein the desired pattern of photocured gradient index optical elements comprises at least one annular ring of photocured gradient index optical elements.

5. The method of claim 4 , wherein the desired pattern of photocured gradient index optical elements comprises a plurality of concentric annular rings of the photocured gradient index optical elements.

6. 4. The method of claim 3, further comprising the steps of: modeling a desired asymmetric refractive index distribution for each of the at least one light-cured gradient index optical element; and determining at least one light exposure condition required to produce the desired asymmetric refractive index distribution.

7. The method of claim 6 , wherein the modeled desired asymmetric refractive index profile for each of the at least one light cured gradient index optical element is defined by an asymmetric polynomial function.

8. The method of claim 7 , wherein the modeled desired asymmetric refractive index profile results in an asymmetric refractive index profile that varies radially in a plane parallel to a surface of the film.

9. The method of claim 6 , wherein the modeled desired refractive index profile results in an asymmetric refractive index profile that varies in at least one linear direction parallel to a surface of the film.

10. The method of claim 6 , wherein the modeled desired refractive index profile results in an asymmetric refractive index profile that varies circumferentially in a plane parallel to a surface of the film.

11. The method of claim 6 , wherein the modeling step comprises modeling at least two different desired refractive index profiles for at least two different light cured gradient index optical elements.

12. 7. The method of claim 6, wherein the modeling step includes selecting a desired refractive index profile for each of the at least one light-cured gradient index optical element depending on a position of the optical element within a desired pattern of the light-cured gradient index optical elements.

13. The method of claim 6 , wherein the modeling step comprises measuring or plotting a map of refractive index change as a function of light exposure conditions.

14. The method of claim 13 , wherein the modeling step includes converting the refractive index variation map into a digital light projection intensity map for controlling the projection of light onto the film.

15. The method of claim 14 , further comprising determining whether the digital light projection system produces a non-linear response and incorporating the non-linear response into the digital light projection intensity.

16. The method of claim 6 , wherein the desired asymmetric refractive index profile for each of the at least one photocured gradient index optical element results in a photocured gradient index optical element having a diameter or width between 1 μm and 5 mm.

17. The method of claim 1 , wherein the digital light projection system comprises a digital mirror device.

18. The method of claim 1 , wherein the digital light projection system has an illumination wavelength between 440 nm and 660 nm.

19. The method of claim 1 , wherein the digital light projection system has a pixel resolution of less than 100 μm.

20. The method of claim 1 , wherein the film is applied to a surface of the lens after creation of the at least one photohardened gradient index optical element.

21. The method of claim 1 , wherein the step of applying the film to a surface of the lens comprises the step of adhering the film to the lens with an adhesive.

22. The method of claim 1 , further comprising the step of cutting or shaping the film suitable for application to the ophthalmic lens.

23. The method of claim 1 , wherein the ophthalmic lens is a spectacle lens.

24. The method of claim 1 , wherein the ophthalmic lens is a contact lens.

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