Ophthalmic lens including an asymmetric refractive index distribution type optical element

Abstract

An ophthalmic lens (1), a film used for the ophthalmic lens (1), and a method (500) for manufacturing the ophthalmic lens (1) are disclosed. The lens (1) has an optical axis. The lens (1) includes a layer (3) provided on the surface of a substrate (5). The layer (3) has a base refractive index and includes at least one refractive index distribution type optical element (7a, 7b) having an asymmetric refractive index profile. The at least one refractive index distribution type optical element (7a, 7b) condenses light from a distant point light source on the optical axis to a point at a first distance from the optical axis (2).

Description

Technical Field

[0001] The present disclosure relates to an ophthalmic lens having a layer including at least one refractive index profile element having an asymmetric refractive index profile, a film for use with such a lens, and a method of manufacturing such a lens.

Background Art

[0002] Many people, including children and adults, require ophthalmic lenses to correct myopia (nearsightedness), and many adults require ophthalmic lenses to correct presbyopia (a condition in which the ability to focus on nearby objects is impaired due to age-related decline in accommodation). Ophthalmic lenses may also be required to correct hyperopia (farsightedness), astigmatism, or keratoconus (a condition in which the cornea gradually bulges to form a cone shape).

[0003] Without optical correction, a myopic eye focuses incident light from a distant object at a position in front of the retina. As a result, the light converges toward the front surface of the retina and then diverges beyond it, arriving at the retina out of focus. Conventional lenses for correcting myopia (e.g., spectacle lenses or contact lenses) either reduce convergence (in the case of contact lenses) or introduce divergence of the incident light from a distant object before it reaches the eye (in the case of spectacle lenses), thereby shifting the focal position onto the retina.

[0004] In presbyopic eyes, the lens cannot effectively change its shape to accommodate nearby objects, so presbyopic people cannot focus on nearby objects. Conventional lenses for correcting presbyopia (e.g., spectacle lenses or contact lenses) include bifocal lenses or progressive lenses that include a region optimized for near vision and a region optimized for far vision. Presbyopia can also be treated using bifocal lenses, multifocal lenses, or monovision lenses (different prescriptions are provided for each eye, with a farsighted lens provided in one eye and a nearsighted lens provided in the other eye).

[0005] Decades ago, it was proposed that the progression of myopia in children and young people could be slowed or prevented by undercorrection, i.e., bringing the focus closer to the retina but not all the way onto the retina. However, this approach necessarily results in a reduction in distance vision compared to the visual acuity obtained with lenses that fully correct myopia. Furthermore, it is now considered doubtful that undercorrection is effective in controlling the progression of myopia. More recent approaches involve providing lenses that have both a region for full correction of distance vision and a region for undercorrection, i.e., intentionally inducing myopic defocus. Lenses can also be provided that increase the scattering of light in specific regions compared to the light passing through the fully corrected region of the lens. These approaches have been suggested to be able to prevent or slow the onset or progression of myopia in children and young people while providing good distance vision.

[0006] In the case of lenses having a region that provides defocus, the region that provides full correction of distance vision is typically referred to as the base refractive power region, and the region that provides undercorrection or intentionally induces myopic defocus is typically referred to as the additional refractive power region or the myopic defocus region (the refractive power being more positive or less negative than the refractive power (diopters) of the base refractive power region that corrects distance vision). The surface of the additional refractive power region (typically the front surface) has a smaller radius of curvature than the radius of curvature of the distance refractive power region and thus provides a more positive or less negative refractive power (diopters) to the eye. The additional refractive power region is designed to focus incoming parallel light (i.e., light from far away) in front of the retina (i.e., closer to the lens) in the eye. The distance refractive power region is designed to focus light to form an image on the retina (i.e., further from the lens). When the wearer of the lens uses an adjustment function to focus the light passing through the distance refractive power region while looking at a nearby object, the additional refractive power region will focus the light in front of the retina.

[0007] In the case of a lens that increases light scattering in a specific region, the feature that increases scattering can be introduced into the lens surface or, alternatively, into the material used to form the lens. For example, scattering elements can be generated by thermal, mechanical, or photoinduced methods on the lens surface or can be embedded within the lens. The scattering elements can be, for example, laser-induced material changes for forming optical elements embedded in the lens material.

[0008] A known type of contact lens that reduces the progression of myopia is a bifocal contact lens available under the name MISIGHT (CooperVision, Inc.). This bifocal lens is configured with a given optical dimension that can provide the use of distance correction (i.e., base refractive power) to see both distant and near objects, unlike bifocal and multifocal contact lenses configured to improve the vision of presbyopia. The treatment zone of the bifocal lens with additional refractive power provides a myopic defocused image at both far and near viewing distances.

[0009] These lenses have been found to be beneficial in preventing or delaying the onset or progression of myopia, but the annular additional refractive power region can cause undesired visual side effects. Light focused by the annular additional refractive power region in front of the retina diverges from the focus and forms a defocused (blurred) ring on the retina. Thus, wearers of these lenses may see a ring or "halo" around the image formed on the retina, especially in the case of small and bright objects such as streetlights and car headlights. Also, instead of using the eye's natural accommodation (i.e., the natural ability of the eye to change the focal length) to focus on near objects, theoretically, the wearer may utilize the additional annular additional refractive power region to focus on near objects. This means, in other words, that the wearer may unconsciously (without awareness) use the lens in the same manner as when a presbyopia-correcting lens is used, which is not desirable for young subjects.

[0010] Additional lenses have been developed that can be used for the treatment of myopia. In such lenses, an annular region is configured so that an on-axis image is not formed in front of the retina, thereby preventing such an image from being used to focus on nearby targets and causing the eye to accommodate. Instead, a distant point source is imaged by the annular region as a ring-shaped focal line on an additional refractive power focal plane near the eye, resulting in a small spot size of light on the retina of the distant focal plane without a surrounding "halo" effect.

[0011] It is recognized that it may be beneficial to provide lenses that introduce additional myopic defocus to treat myopia. It may be beneficial to provide lenses that provide an extended depth of focus to treat presbyopia.

[0012] It is recognized that known lenses that include a treatment portion for introducing defocus are typically designed to provide a specific treatment to the lens wearer. Such lenses can be expensive and have a complex design, and if the requirements of the lens wearer change over time, it may be necessary to purchase different lenses that provide different levels of correction.

[0013] The present invention aims to provide a simple and cost-effective alternative to known lenses that is used to prevent or delay the progression of myopia. Such lenses may also be beneficial for correcting or improving vision related to presbyopia, hyperopia, astigmatism, keratoconus, or other refractive anomalies. SUMMARY OF THE INVENTION

[0014] In a first aspect, the present disclosure provides an ophthalmic lens according to claim 1.

[0015] In a second aspect, the present disclosure provides a film according to claim 22.

[0016] In a third aspect, the present disclosure provides a method according to claim 23.

[0017] Of course, it will be understood that features described in connection with one aspect of the present disclosure may be incorporated into other aspects of the present disclosure. For example, the methods of the present disclosure may incorporate features described with reference to the apparatus of the present disclosure, and vice versa.

[0018] Exemplary embodiments are described for illustrative purposes only with reference to the accompanying schematic diagrams.

Brief Description of the Drawings

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DETAILED DESCRIPTION OF THE INVENTION

[0039] According to a first aspect, the present disclosure provides an ophthalmic lens having an optical axis. The lens includes a layer provided on a surface of a substrate. The layer has a base refractive index and includes at least one refractive index distribution type optical element having an asymmetric refractive index profile. The at least one refractive index distribution type (GRIN) optical element converges light from a distant point light source on the optical axis to a point at a first distance from the optical axis of the lens.

[0040] The optical axis of the lens is defined with reference to a distant (far away) point light source. Light from a distant point light source on the optical axis of the lens (hereinafter may be referred to as an on-axis distant point light source) will be focused on the optical axis of the lens. The optical axis may exist along the center line of the lens. For example, when the lens is a contact lens, the optical axis usually exists along the center line of the lens. However, it is of course possible that the optical axis does not exist along the center line of the lens. This may apply to the case of spectacle lenses. In the case of spectacle lenses, 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 geometry of the lens.

[0041] The lens can be a lens for preventing or delaying the onset or progression of myopia. The lens can be a lens for correcting or improving vision related to presbyopia, hyperopia, astigmatism, keratoconus, or other refractive abnormalities.

[0042] The layer may cover the entire surface of the lens or may cover substantially the entire surface of the lens. Alternatively, the layer may cover a part of the surface of the lens. The layer may cover the central portion of the surface of the lens, for example, the portion configured to be located in front of the eye of the lens wearer when the lens is in use. The layer may cover an annular region of the surface surrounding the center of the lens. There may be a peripheral region of the lens not covered by the layer.

[0043] The base refractive index of the layer can be uniform. The base refractive index of the layer can be from 1.3 to 1.8, preferably about 1.5. Each of at least one GRIN optical element can have an average refractive index greater than the base refractive index. Alternatively, each of at least one GRIN optical element can have an average refractive index less than the base refractive index. Light passing through the layer from an on-axis distant point source will be focused at a focal point on the optical axis of the lens. The base refractive power focal plane can be defined as the surface perpendicular to the optical axis of the lens and passing through the said focal point of the lens. As used herein, the term "surface" does not refer to a physical surface but to a surface that can be depicted as passing through a plurality of points at which light from a distant object is focused. Such a surface is also called an image plane (which can be curved but is so named) or an image shell. The eye focuses light on a curved retina, and in a fully focused eye, the curvature of the image shell coincides with the curvature of the retina. Thus, the eye does not focus light on a mathematically flat plane. However, in the art, the curved surface of the retina is generally referred to as a "plane". Light from an on-axis point source passing through the layer is focused at the focal point on the optical axis of the lens, i.e., the base refractive power focal plane.

[0044] In the context of the present disclosure, each of the at least one GRIN optical element is an element having a varying refractive index and a refractive index profile that is asymmetric in a plane parallel to the surface of the layer as a consequence of the varying refractive index. Each element can be substantially cylindrical or can be cylindrical with an elliptical or oval cross-section, and the axis of the cylinder can be perpendicular to the plane of the layer. Each element can be substantially spherical or substantially cubic. Each element can have a cross-section that is circular, elliptical, oval, or square in a plane parallel to the surface of the layer. Each element can have a flat surface that is flush (at the same height) with the surface of the layer and has a circular, elliptical, oval, or square cross-section. In some embodiments of the present disclosure, the change in refractive index across 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 profile, light passing through the at least one GRIN optical element from an off-axis distant point source is directed to a point that is not on the optical axis of the lens (i.e., an off-axis focal point).

[0045] Each of the at least one GRIN optical element is a lens having its own local optical axis that is tilted with respect to the optical axis of the lens as a result of the asymmetric refractive index profile. The local optical axis of each of the at least one GRIN optical element is defined with respect to an off-axis distant point source. Light from an off-axis distant point source (hereinafter, may be referred to as an on-axis distant point source) that is on the local optical axis of a GRIN optical element will be focused on the local optical axis of the GRIN optical element. A GRIN optical element having an asymmetric change in refractive index in a direction parallel to the surface of the layer (i.e., a lateral direction) will have a local optical axis that is tilted with respect to the optical axis of the layer of the lens having a base refractive index. As a result, light passing through each of the GRIN optical elements from an on-axis distant point source will be focused at a point that is at a first distance from the optical axis of the lens. The focusing power of each of the GRIN optical elements will depend on the refractive index profile of the GRIN optical element.

[0046] Any or all of the at least one GRIN optical element(s) may be configured such that light rays passing through the GRIN optical element from an on-axis distant point source form a small spot of light centered on the optical axis of the lens at the base refractive power focal plane. Thus, each of the GRIN optical elements can focus light towards an off-axis focus, but an approximate superposition of an image formed from light passing through a region of a lens having a 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 formed on the retina and can improve the visual acuity of the lens wearer. Alternatively, any or all of the at least one GRIN optical element(s) may be configured such that light passing through the GRIN optical element from an on-axis distant point source does not intersect the optical axis of the lens at the base refractive power focal plane. This can reduce the contrast of the image formed on the retina or degrade the image quality of the image and may be advantageous for suppressing the progression of myopia.

[0047] The asymmetric change in refractive index can be a radial (radial direction) change in refractive index. That is, the refractive index can change within a plane parallel to the surface of the layer (i.e., a cross-section) as it extends radially (radially) outward from the central point of the GRIN optical element. The asymmetric change in refractive index can be a circumferential change. That is, the refractive index can change within a plane parallel to the surface of the layer along the circumference of the GRIN optical element, and the change in refractive index can be different along different meridians of the GRIN optical element.

[0048] The asymmetric change in refractive index can be a linear change in a direction parallel to the surface of the layer.

[0049] The asymmetric change in refractive index can be a combination of a linear change and a radial and / or circumferential change within a cross-section.

[0050] Advantageously, the GRIN element can provide defocus. Defocus is thought to be useful in preventing or delaying the worsening of myopia. Defocus is also thought to be useful in correcting or improving vision associated with presbyopia, hyperopia, astigmatism, keratoconus or other refractive anomalies. The GRIN optical element can be arranged such that it provides a random refractive index modulation across the layer, thereby increasing the spread of light across the entire retina and reducing the contrast of the image.

[0051] The change in refractive index of any of the at least one GRIN optical element can be defined by an asymmetric polynomial function.

[0052] The layer can include a plurality of GRIN optical elements. The layer can include a plurality of GRIN elements randomly dispersed throughout the layer. The plurality of GRIN optical elements can be randomly dispersed across a portion of the layer. The layer can include a plurality of GRIN optical elements arranged to form at least one annular ring. The at least one annular ring can be circular, elliptical, or oval. The at least one annular ring can be centered on the optical axis of the lens. The plurality of GRIN optical elements can be arranged to form at least two concentric annular rings positioned at different radial distances from the optical axis of the lens.

[0053] In the case of spectacle lenses, it can be advantageous for the GRIN optical elements to be dispersed across a relatively wide area of the lens. This can enable the defocus provided by the GRIN optical elements to be maintained when the wearer's eye moves relative to the lens. The plurality of GRIN optical elements dispersed across the entire spectacle lens can enable a consistent myopic defocus to be maintained.

[0054] The GRIN optical elements can be positioned at regular intervals across the whole or a part of the layer. The GRIN optical elements can be arranged on the lattice points of a triangular lattice. The GRIN optical elements can be arranged on the lattice points of a square or rectangular lattice.

[0055] The GRIN optical element can be arranged to form an annular pattern on the layer. The annular pattern can leave the central region of the lens as a region where no GRIN optical element exists. The lens can have a central region with a maximum diameter of 8 mm where no GRIN optical element is provided. The annular pattern can have a single annular portion or a plurality of concentric annular portions.

[0056] The layer can include at least one second annular ring of GRIN optical elements positioned at different radial distances from the optical axis of the lens.

[0057] At least two of the GRIN optical elements can be substantially identical, i.e., they can have the same size and shape and can have the same asymmetric refractive index profile. In this case, the at least two GRIN optical elements can focus light from an off-axis distant point source onto a plurality of points that are not on the optical axis of the lens but on the same focal plane. The refractive index profile of the at least two GRIN elements can change such that when the lens is positioned on the eye, the light passing through the GRIN optical element from an off-axis distant point source is focused on a surface that is closer to the rear surface of the lens than the base refractive power focal plane (is focused). The refractive index profile of the at least two GRIN elements can change such that when the lens is positioned on the eye, the light passing through the GRIN optical element from an off-axis distant point source is focused on a surface that is farther from the rear surface of the lens than the base refractive power focal plane.

[0058] Substantially identical GRIN optical elements positioned at the same radial distance from the optical axis of the lens (e.g., GRIN optical elements disposed within a circular concentric ring centered on the optical axis) can focus light toward a plurality of off-axis points that are equidistant from the optical axis of the lens and lie on the same focal plane. Thus, the plurality of foci formed from the light passing through these GRIN optical elements can form a circular ring on a focal plane. Similarly, substantially identical GRIN optical elements can be arranged to form an elliptical or oval ring centered on the optical axis, and the plurality of foci formed from the light from an off-axis distant point source passing through these GRIN optical elements can form an elliptical or oval ring on a focal plane.

[0059] At least two of the GRIN optical elements can have different asymmetric refractive index profiles. In this case, the at least two GRIN optical elements will have different local optical axes. In the case of a first and a second GRIN element having different refractive index profiles and positioned at the same radial distance from the optical axis of the lens, the light from an off-axis distant point source passing through the first GRIN optical element can be focused at a point that is a first distance away from the optical axis of the lens, and the light from an off-axis distant point source passing through the second GRIN optical element can be focused at a point that is a second different distance away from the optical axis of the lens. The focus of each GRIN optical element will depend on the asymmetric refractive index profile of the GRIN optical element and the position of the GRIN optical element.

[0060] At least two of the GRIN optical elements having different refractive index profiles can focus light toward different focal planes.

[0061] 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, and the other (remaining) GRIN optical elements may have different changes in refractive index. The plurality of GRIN optical elements may be dispersed such that GRIN optical elements having the same or similar changes in refractive index can be grouped into clusters or regular arrangements. The layer may be divisible into a plurality of distinguishable portions, each portion including GRIN optical elements having the same or similar changes in refractive index.

[0062] There may be a correlation between the refractive index profile of each of the at least one GRIN optical element and the radial position of the element from the optical axis of the lens. GRIN optical elements positioned at the same radial distance from the optical axis of the lens (e.g., elements positioned around a circular ring centered on the optical axis of the lens) may have the same refractive index profile. GRIN optical elements positioned at different radial distances from the optical axis of the lens may have different refractive index profiles.

[0063] A GRIN optical element positioned at a greater radial distance from the optical axis of the lens may have a refractive index profile resulting in a greater focusing power than a GRIN optical element positioned at a smaller radial distance from the optical axis of the lens. When the lens is in use, a GRIN optical element positioned at a greater radial distance from the optical axis of the lens may focus light from an off-axis distant point source onto a surface closer to the rear surface of the lens than a GRIN optical element positioned at a smaller radial distance from the optical axis of the lens.

[0064] The lens may comprise a plurality of GRIN optical elements that form a first circular ring centered on the optical axis of the lens, and these GRIN optical elements may have a first refractive index profile. The lens may comprise a GRIN optical element that forms a second circular ring centered on the optical axis of the lens at a radial distance greater than that of the first circular ring, and these GRIN optical elements may have a different second refractive index profile. The first refractive index profile may result in the GRIN optical elements forming part of the first circular ring focusing light towards a first focal plane. The second refractive index profile may result in the GRIN optical elements forming part of the second circular ring focusing light towards a second focal plane. When the lens is worn (mounted) 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 closer to the rear surface of the lens than the second focal plane. The first focal plane may be further away from the rear surface of the lens than the second focal plane.

[0065] The lens may comprise GRIN optical elements that form a plurality of concentric annular rings. The GRIN optical elements within the same annular ring may have the same refractive index profile. The GRIN optical elements that form different annular rings may have different refractive index profiles. An annular ring positioned at a greater radial distance from the optical axis of the lens may include GRIN optical elements having a refractive index change that results in a greater focusing power for that element. When the lens is in use, an annular ring positioned at a greater radial distance from the optical axis of the lens may include GRIN optical elements that focus light towards a surface closer to the rear surface of the lens than an annular ring positioned at a smaller radial distance from the optical axis of the lens. Alternatively, an annular ring positioned at a greater radial distance from the optical axis of the lens may include GRIN optical elements having a smaller focusing power. When the lens is in use, an annular ring positioned at a greater radial distance from the optical axis of the lens may include GRIN optical elements that focus light towards a surface further away from the rear surface of the lens than an annular ring positioned at a smaller radial distance from the optical axis of the lens.

[0066] Each of the at least one GRIN optical element(s) can cause additional scattering of light incident on the GRIN optical element(s) compared to the light incident on the remainder of the layer.

[0067] Each of the at least one GRIN optical element(s) can have a minimum refractive index difference of at least 0.001, preferably at least 0.005, compared to the base refractive index. Each of the at least one GRIN optical element(s) can have a minimum refractive index that is 0.001 greater than the base refractive index. Each of the at least one GRIN optical element(s) can have a minimum refractive index that is 0.005 greater than the base refractive index. Each of the at least one GRIN optical element(s) can have a maximum refractive index that is 0.005 less than the base refractive index. Each of the at least one GRIN optical element(s) can have a maximum refractive index that is 0.001 less than the base refractive index. Each of the at least one GRIN optical element(s) can have a maximum refractive index difference of less than 0.1, preferably less than 0.025, compared to the base refractive index. Each of the at least one GRIN optical element(s) can have a maximum refractive index that is 0.1 greater than the base refractive index. Each of the at least one GRIN optical element(s) can have a maximum refractive index that is 0.025 greater than the base refractive index. Each of the at least one GRIN optical element(s) can have a minimum refractive index that is 0.1 less than the base refractive index. Each of the at least one GRIN optical element(s) can have a minimum refractive index that is 0.025 less than the base refractive index. Each of the at least one GRIN optical element(s) can have a minimum refractive index equal to the base refractive index. Each of the at least one GRIN optical element(s) can have a minimum refractive power of -25D to +25D, preferably -0.25D to +25.0D. In the case of a lens used to prevent or delay the onset or progression of myopia, each GRIN optical element can have a minimum refractive power of -0.25 to +25.0D. In the case of a lens used to prevent or delay the onset or progression of hyperopia, each GRIN optical element can have a minimum refractive power of 0.0 to -25.0D.

[0068] The layer has a finite thickness. Each of at least one GRIN optical element may extend through the thickness of the layer. Each of at least one GRIN optical element may extend up to the middle of the thickness of the layer. Each of at least one GRIN optical element may be embedded within the layer. The thickness of the layer may be uniform. Each of at least one GRIN optical element may be embedded within the layer with no variation in the thickness of the layer, or may be embedded within the layer with a variation in the thickness of the lens. Each of at least one GRIN optical element may have a uniform thickness. Each of at least one GRIN optical element may have a planar surface that is flush (at the same height) with the surface of the layer.

[0069] The layer may be a crosslinked polymer layer containing at least one GRIN optical element. The layer may be formed from a matrix of uncrosslinked polymer. The layer may be bonded to a substrate. The layer may be bonded to the substrate using plasma. The layer may be adhered to the substrate. The layer may be adhered to the substrate using a curable adhesive.

[0070] The layer may be provided on the front surface of the substrate. The layer may be provided on the rear surface of the substrate. The layer may be provided on both the front and rear surfaces of the substrate. The layer may be a film applied to the surface of the substrate. The layer may include Bayfol® HX film. The layer may be a film applied to the substrate during the manufacture of the lens. The layer may be removably adhered or otherwise applied to the substrate, i.e., it may be easily removable from the lens. The layer may be reusable, i.e., the layer may be easily removed and reapplied to the same or a different substrate.

[0071] The layer may be a coating provided on the surface of the substrate. The coating may be applied to the substrate during the manufacturing process of the substrate. The coating may be sprayed onto the substrate. The coating may bond to the surface of the substrate. The coating may be irreversibly applied to the lens, for example, the bond between the coating and the substrate may be a permanent bond.

[0072] The substrate may be a film for applying (sticking) to the surface of the lens. The film may be a flexible and transparent film. In the case of a contact lens, the film may have a thickness of 1 μm to 100 μm, preferably 10 μm to 20 μm, more preferably 14 μm to 18 μm. In the case of an eyeglass lens, the film may have a thickness of 1 μm to 1000 μm, preferably 10 μm to 20 μm, more preferably 14 μm to 18 μm.

[0073] The film may be applied to the front surface of the lens.

[0074] The substrate may be applied to the lens during the manufacturing of the lens. The substrate may be removably adhered or otherwise applied to the lens, that is, it may be easily removable from the lens. The substrate may be reusable, that is, the substrate may be easily removed and reapplied to the same lens or a different lens.

[0075] Alternatively, the substrate may be a lens.

[0076] The lens may be an eyeglass lens. The eyeglass lens may include PMMA, CR-39, polycarbonate, Trivex, or crown glass. The lens may be a contact lens. The layer may be provided on the front surface of the lens. In the context of the present disclosure, the front surface of the lens is the forward-facing surface or the outer surface of the lens when the lens is being worn by the lens wearer.

[0077] The lens can be circular in shape. The lens can be elliptical in shape. The lens can be oval in shape. The lens can be rectangular in shape. The lens can be square in shape. The front surface of the lens is 1200mm 2 ~3000mm 2 and can have an area of. The lens can be formed from a hard plastic such as clear glass or polycarbonate. The lens can be substantially planar and can have at least one curved surface that provides lens refractive power.

[0078] The lens can be a contact lens. As used herein, the term contact lens refers to an ophthalmic lens that can be placed on the front surface of the eye. It will be understood that such contact lenses provide clinically acceptable on-eye movement and do not bind to the human eye. The contact lens can be in the form of a corneal lens (e.g., a lens that sits on the cornea of the eye). In embodiments where the lens is a contact lens, the lens can have a surface area of 60mm 2 ~750mm 2 and can have a circular shape. The lens can have an oval shape. The lens can have an elliptical shape. The lens can have a diameter of 10mm to 15mm.

[0079] The lens can be a hard contact lens. The lens can be a gas (oxygen) permeable hard contact lens.

[0080] The contact lens can be a toric contact lens. For example, a toric contact lens can include an optical zone shaped to correct a person's astigmatism. The lens can be a scleral contact lens.

[0081] The lens can be a soft contact lens, such as a hydrogel contact lens or a silicone hydrogel contact lens.

[0082] The lens may include an elastomer material, a silicone elastomer material, a hydrogel material, or a silicone hydrogel material, or a combination thereof. As understood in the field of contact lenses, a hydrogel is a material that retains water in an equilibrium state and does not contain a silicone-containing compound. A silicone hydrogel is a hydrogel that contains a silicone-containing compound. As described in the context of the present disclosure, the hydrogel material and the silicone hydrogel material have an equilibrium water content (EWC) of at least 10% to about 90% (wt / wt). In some embodiments, the hydrogel material or the silicone hydrogel material has an EWC of about 30% to about 70% (wt / wt). In comparison, as described in the context of the present disclosure, the silicone elastomer material has a water content of about 0% to less than 10% (wt / wt). Typically, the silicone elastomer material used in the present method or apparatus has a water content of 0.1% to 3% (wt / wt).Examples of suitable lens formulations (compositions) include those having the following United States Adopted 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, 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, rayfilcon A, etc.

[0083] Alternatively, the lens can comprise, consist essentially of, or consist of a silicone elastomer material. For example, the lens can 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 understood by those skilled in the art. Other silicone elastomer materials can be obtained, for example, from NuSil Technology, or from Dow Chemical Company.

[0084] The lens may have an optical zone. The optical zone includes a lens portion having an optical function. The optical zone is configured to be positioned above or in front of the pupil of the eye during use. The optical zone may be surrounded by a peripheral zone. The peripheral zone is outside the optical zone rather than being a part of the optical zone. In the case of a contact lens, when the lens is worn, the peripheral zone may be located above the iris. The peripheral zone may provide mechanical functions such as, for example, increasing the size of the lens, thereby facilitating handling of the lens. In the case of a contact lens, the peripheral zone may provide ballasting (stability) to prevent rotation of the lens and / or may provide a shaped area that improves the comfort of the lens wearer. The peripheral zone may extend to the edge of the lens. In an embodiment of the present disclosure, the layer including at least one GRIN optical element may cover the optical zone but may not cover the peripheral zone.

[0085] The layer may have a uniform thickness. In the case of a contact lens, the layer may have a thickness of 1 μm to 100 μm, preferably 10 μm to 20 μm, more preferably 14 μm to 18 μm. In the case of an eyeglass lens, the layer may have a thickness between 1 μm and 1000 μm, preferably between 10 μm and 20 μm, more preferably 14 μm to 18 μm.

[0086] The layer may be a photopolymer layer. Each of the at least one refractive index distribution type optical element may be a photocured refractive index distribution type optical element. Each of the GRIN optical elements may be formed using a photocuring method.

[0087] Each of the at least one GRIN optical element may have a width of 1 μm to 5 mm, preferably 10 μm to 2 mm. Each of the at least one GRIN optical element has a volume of 1 μm 3 ~5 mm 3 preferably 10 μm 3 ~2 mm 3It may have a volume. The plurality of GRIN optical elements may occupy 5% to 80% of the volume of the layer. The plurality of GRIN optical elements may cover 20% to 80% of the surface area of the layer. The layer may include 2 to 5000 GRIN optical elements.

[0088] The lens may have a central region and an annular region surrounding the central region. The layer may cover a part of the annular region. The layer may not cover the central region, and thus there may be no GRIN optical element in the central region. The layer may cover the entire annular region or may cover a part of the annular region. As used herein, the term annular region refers to a region that may extend around the entire outer edge of the central region or a region that may partially extend around 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 dispersed around the entire annular region or may be dispersed around a part of the annular region.

[0089] The layer may include a plurality of concentric annular regions radially separated by regions of the layer having a base refractive index.

[0090] The lens may further include an adhesive provided between the layer and the surface of the substrate. The adhesive may include a transparent adhesive such as an epoxy-based adhesive. The adhesive may be an adhesive layer. The adhesive layer may be applied to the front surface of the substrate during the manufacture of the lens. The adhesive may permanently adhere the layer to the surface of the substrate. Alternatively, the layer may be bonded to the surface of the substrate. The layer may be permanently or irreversibly bonded to the surface of the substrate.

[0091] The lens may further comprise a protective layer disposed on a front surface of the layer including at least one gradient index optical element. The front surface of the layer including at least one GRIN optical element faces forward or is the outer surface of the layer when the lens is worn by a lens wearer under normal use conditions. The protective layer may cover all or a portion of the front surface of the layer including at least one GRIN optical element. The protective layer may be a transparent layer. The protective layer may include polycarbonate (PC). The protective layer may include polyethylene terephthalate (PET) or triacetate cellulose (TAC). The protective layer may include 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 adhered to the layer including at least one GRIN optical element using an adhesive.

[0092] According to a second aspect, the present disclosure provides a film for use as a layer of an ophthalmic lens. The lens has an optical axis. The lens includes a substrate. The lens may include any of the features described above. The film includes at least one gradient index optical element having a base refractive index and an asymmetric refractive index profile. The film may be provided on a surface of a lens substrate, with at least one of the gradient index optical elements configured to focus light from a distant point source on the optical axis toward a point a first distance from the optical axis.

[0093] The film may have any of the properties of the layers described above. Advantageously, the film may be applied over a wearer's existing lenses, thereby reducing the cost of the treatment.

[0094] The film may be a crosslinked polymer thin film that includes at least one gradient index optical element. The film may be formed from a matrix of a non-crosslinked polymer. The film may be a Bayfol® HX film.

[0095] The film can be cut, formed, or shaped so as to have an area suitable for application to spectacle lenses or contact lenses. The film can be configured for use in spectacle lenses, i.e., it can be sized and shaped, and have an area of 300 mm 2 ~5000 mm 2 and preferably 1000 mm 2 ~3000 mm 2 . The film can be for use in applying to spectacle lenses and can be circular, oval, elliptical, square, or rectangular. The film can be configured for use in applying to contact lenses, i.e., it can be sized and shaped, and have an area of 60 mm 2 ~750 mm 2 . The film can be for use in applying to contact lenses and can be circular, oval, elliptical, square, or rectangular. The film can be for use in applying to contact lenses and can have a diameter of 6 mm to 20 mm, preferably 9 mm to 16 mm.

[0096] The film can have a uniform thickness. In the case of contact lenses, the film can have a thickness of 1 μm to 100 μm, preferably 10 μm to 20 μm, more preferably 14 μm to 18 μm. In the case of spectacle lenses, the film can have a thickness of 1 μm to 1000 μm, preferably 10 μm to 20 μm, more preferably 14 μm to 18 μm.

[0097] Each of at least one refractive index distribution type optical element can be a photocured optical element. Each of the refractive index distribution type optical elements can be formed using a photocuring method. Each of the refractive index distribution type optical elements can be formed using a photocuring method using a digital light projection system, a direct laser writing system, or a collimated LED or laser light source. A high-resolution 3D photocuring system such as a two-photon confocal microscope-based laser illumination system can be used to photocure each of the GRIN elements.

[0098] The film can be configured to be easily removable from the ophthalmic lens. The film can be reusable, i.e., the film can be easily removed and reapplied to the same lens or a different lens. Advantageously, this can allow for flexibility in the prescription of the lens wearer. This is because the film can be attached to / removed from the existing lens even when the prescription changes.

[0099] The film can have an adhesive surface for adhering to the surface of the lens substrate. Before application to the lens substrate, the adhesive surface of the film can be covered by a protective film. The protective film can include a polymer such as polyethylene terephthalate (PET), polyethylene (PE), or triacetyl cellulose (TAC). The protective film can be transparent. The protective film can be a flexible film. The adhesive surface can be a layer of an adhesive such as an epoxy-based adhesive.

[0100] The film can be provided on a substrate. The substrate can contact the first surface of the film, and the second surface opposite the film can be the adhesive surface. Thus, when the film is adhered to the ophthalmic lens using the adhesive surface, when the film is applied to the lens, the substrate can be the front surface / front-facing surface / external surface of the lens film. The substrate can be configured to provide a protective layer when the film is applied to the surface of the ophthalmic lens. The substrate can include polycarbonate (PC). The substrate can include polyethylene terephthalate (PET) or triacetyl cellulose (TAC). The substrate can include a substance having negligible birefringence. The substrate can be impermeable to water. The substrate can be scratch-resistant. The substrate can have a base refractive index. The substrate can provide a certain degree of UV protection.

[0101] According to a third aspect, the present disclosure provides a method of manufacturing an ophthalmic lens. The lens has an optical axis. The lens includes a layer provided on a surface of a substrate. The layer has a base refractive index and includes at least one refractive index profile type optical element having an asymmetric refractive index profile. The at least one refractive index profile type optical element condenses light from a distant point light source on the optical axis toward a point at a first distance from the optical axis. The lens may include any of the foregoing features. The method includes providing a lens having an optical axis. The method includes providing a layer having a base refractive index, the layer including at least one refractive index profile type optical element having an asymmetric refractive index profile. The method includes applying the layer to a surface of a lens substrate such that light from a distant point light source on the optical axis passing through the layer is condensed at a point on the optical axis, and light from a distant point light source on the optical axis passing through the at least one refractive index profile type optical element is condensed at a point at a first distance from the optical axis.

[0102] The manufacturing of the lens may include forming a female member having a concave lens forming surface and a male member having a convex lens forming surface. The method may include filling a gap between the female member and the male member with a bulk lens material. The method may further include curing the bulk lens material to form a lens.

[0103] The lens may be a molded contact lens. The lens may be formed by a casting (molding) process, a spin casting process, a lathe machining process, or a combination thereof. As will be understood by those skilled in the art, casting refers to a lens forming process by disposing a lens forming material between a female member having a concave lens member forming surface and a male member having a convex lens member forming surface.

[0104] The manufacture of the lens may include a step of applying (coating) an adhesive to the surface of the substrate, and a step of applying the layer to the surface of the lens substrate using the adhesive. The manufacture of the lens may include a step of bonding the layer to the surface of the lens substrate. The manufacture of the lens may include a step of applying (coating) an adhesive to the surface of the layer, and a step of applying the layer to the lens using the adhesive. The method may include a step of cutting, forming or shaping the layer so as to have an area suitable for application to an ophthalmic lens or a contact lens.

[0105] The step of providing the layer may include a step of providing a photocurable film. The step of providing the film may include a step of photocuring at least one region of the film using a digital light projection system, thereby generating at least one photocured refractive index distribution type optical element.

[0106] In the context of the present disclosure, a photocured GRIN optical element is a GRIN element formed by photocuring or photopolymerization. The photocured GRIN optical element may be generated from a photopolymerizable or photocurable molecule, or other photocurable elements. The photocuring may result in a refractive index that varies laterally across the photocured region. The photocurable molecules may be dispersed within the film. The photocurable molecules may be dispersed within the matrix of a crosslinked polymer or within a resin.

[0107] In the context of the present disclosure, a digital light projection (DLP) system is a light irradiation system used to direct light towards a photocurable film, thereby enabling a certain area of the film to be photocured. The DLP system used has a wavelength suitable for the photopolymerization or photocuring of the target film material. For example, in the case of Bayfol® HX film, the DLP system can have a wavelength in the range of 440 nm to 660 nm. The pixel resolution of the DLP system can be less than 100 μm, preferably less than 30 μm, more preferably less than 10 μm. The DLP system can be a commercially available DLP system, for example, a 3DLP9000-LED.9” WQXGA light engine with a wavelength of 460 nm and a pixel resolution of 30 nm. The DLP system can include a microelectromechanical system (MEMS). The DLP system can include a digital micromirror device. The digital micromirror device can direct light and / or control the transmission of light towards the film.

[0108] The DLP system can be used to illuminate the entire film or a certain area of the film. The DLP system can be used to photocure individual photocurable elements or molecules, or a plurality of individual photocurable molecules. The plurality of individual photocurable molecules can be photocured continuously or simultaneously. The DLP system can be used to illuminate an annular area of the film or a plurality of concentric annular areas of the film.

[0109] The process of using a digital light projection system may include a process of using a grayscale image to control the projection of light onto a film. The grayscale image may provide a template for projecting light from the DLP system onto the film. The grayscale image may be a bmp image. The grayscale image may mask some areas of the film so that while at least one area of the film is exposed to light from the DLP system, some areas of the film are not 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 and may produce a photocured GRIN optical element.

[0110] A method of manufacturing a lens may include generating a design of a film, the design having a desired pattern of a GRIN optical element having an asymmetric refractive index profile that is photocured. The method may include generating a grayscale image using the design.

[0111] The grayscale image may be designed to generate any of the above-described arrangements of photocured GRIN elements. Here, the GRIN optical element has an asymmetric refractive index profile. The grayscale image may include a plurality of apertures that allow light from the DLP system to reach the film. The areas of the film irradiated by light from the DLP system may be photocured. The image may include a plurality of portions that block or mask the light from reaching the film. The areas of the film not irradiated by light from the DLP system are not photocured. The image may include a plurality of apertures arranged in a pattern. The desired pattern of photocured GRIN optical elements may be an array of GRIN optical elements arranged on the lattice points of the film. In this case, the image may include a plurality of apertures arranged on the lattice points. The lattice may be a triangular lattice, a square lattice, or a cuboid lattice.

[0112] The method includes modeling a desired asymmetric refractive index profile for each of at least one photo-cured GRIN element, and determining at least one exposure condition required to generate the desired asymmetric refractive index profile.

[0113] Modeling can be utilized to determine the intensity of exposure, and / or the duration of exposure, and / or the wavelength of exposure, required to photo-cure a GRIN element having the desired asymmetric refractive index profile. The conditions can depend on the characteristics of the DLP system, such as the wavelength, intensity, and type of the light source. The conditions can also depend on the characteristics of the film, such as the film material and the thickness of the film. Modeling can be performed using any suitable modeling software, such as MATLAB®. Modeling can be performed using experimental (measurement) data or theoretical (predicted) data. The predicted data can be based on the known characteristics of the film material and / or the DLP system. The desired refractive index profile for each of the photo-cured GRIN elements can be defined by, or approximated by, an asymmetric polynomial function. The desired asymmetric refractive index profile can be modeled for a single photo-cured GRIN element or for multiple photo-cured GRIN elements. In the case of a film including multiple GRIN optical elements, the desired asymmetric refractive index profile for each of at least one photo-cured GRIN element can be the same, or each of the photo-cured GRIN elements can have a different desired asymmetric refractive index profile.

[0114] The modeling process may include the step of measuring or plotting a refractive index change map as a function of exposure conditions. The exposure conditions may be the intensity of light, the exposure duration, or the wavelength of light. The map may be generated as a map having a non-planar surface. The map may be generated as a 3D map. The map may be iteratively updated and / or optimized to generate a desired refractive index profile of the GRIN optical element to be photocured. The map may be a refractive index change map of a single photocured GRIN optical element or a plurality of photocured GRIN optical elements. The map may be used to generate a refractive index distribution type pixel matrix for use in a DLP imaging system. The pixel matrix may specify the required exposure conditions for each pixel of the DLP imaging system to generate the required refractive index change across the entire film. The refractive index distribution type pixel matrix may be configured to generate a single photocured GRIN optical element or 2 to 5000 photocured GRIN optical elements distributed across the entire film. The refractive index distribution type pixel matrix may be configured to generate a plurality of photocured GRIN elements covering 20% to 80% of the area of the film.

[0115] The modeling process may include a process of converting a refractive index change map into a digital light projection intensity map. The digital light projection intensity map may be a pixel matrix of a DLP system. The digital light projection intensity map may be generated from a refractive index distribution type pixel matrix. The digital light projection intensity map may be used when generating a grayscale image for use in a DLP system. The digital light projection intensity map may be used to determine the required exposure conditions for use in a DLP system. The DLP intensity map may be used to generate a bmp image. The image may be an 8-bit image. The exposure conditions may depend on the type of film, the required pattern or arrangement of a plurality of photo-cured GRIN optical elements, the characteristics of the film, and the characteristics of the DLP imaging system. Therefore, the digital light projection intensity map may be used to control the projection of light onto the film by determining the required exposure conditions.

[0116] The method may include a step of exposing the film to light from the DLP using a grayscale image and / or a digital light projection intensity map to control the projection of light across the entire film. The method may include a step of waiting for a minimum time until the film is developed. The method may include a step of flood curing or flood exposing the film using a DLP system or a UV oven after waiting for a minimum time until the film is developed.

[0117] The DLP system may include an optical system that causes a non-linear intensity response. The method may include a step of determining whether a significant non-linear response exists in any pixel or all pixels. If a significant non-linear response exists, the method may include a step of adapting the digital light projection intensity map to take into account the non-linear response.

[0118] For each of at least one GRIN optical element, a desired refractive index profile can result in a photocured GRIN optical element having a diameter of about 1 μm to 5.0 mm. The modeled refractive index profile can be configured to generate at least one photocured GRIN optical element having a diameter of about 1 μm to 5.0 mm. The modeled refractive index profile can be optimized or iteratively optimized to generate at least one photocured GRIN optical element having a diameter of about 1 μm to 5.0 mm. The desired refractive index profile for each of at least one photocured GRIN optical element is 1 μm 3 ~5 mm 3 and can result in a photocured GRIN element having a volume. The desired refractive index profile for each of at least one photocured GRIN optical element can result in a disk-shaped photocured GRIN element or a spherical photocured GRIN element having a profile that is asymmetric in a direction parallel to the surface of the film. The modeled refractive index profile can be optimized or iteratively optimized to generate at least one photocured GRIN optical element having any of the foregoing characteristics.

[0119] The method can comprise applying the film to the surface of a lens or lens substrate after photocuring. The film can be disposed on a second substrate for photocuring and then removed from the second substrate and applied to the lens or lens substrate. The second substrate can be a slide glass. The film can be applied to the surface of the lens before photocuring. The film can be adhered to the surface of the lens using an adhesive such as an epoxy-based adhesive. The adhesive can be an adhesive layer. The adhesive layer can be applied to the front surface of the lens during the manufacture of the lens. The adhesive layer can be applied to the back surface of the film before applying the film to the lens surface. The adhesive can permanently adhere the film to the surface of the lens. The adhesive can removably adhere the film to the surface of the lens.

[0120] Before applying the film to the lens or lens substrate, it may be before or after photocuring the area of the film, but the film can be cut or shaped to be suitable for application to an ophthalmic lens. The film can be cut or shaped to cover the entire surface of the lens or to cover a part of the surface of the lens. The film can be cut or shaped to be circular, oval or elliptical. The film can be cut or shaped to cover the optical zone of the lens or the area of the lens that will be positioned in front of the retina of the lens wearer when the lens is being worn by the lens wearer.

[0121] Before photocuring, a protective layer can be applied to the surface of the film. The method can include a step of removing the protective layer before photocuring. The protective layer can include polypropylene.

[0122] After applying the photocured film to the lens, the method can include a step of applying a protective layer to the front surface of the lens (i.e., on the photocured layer). The protective layer can cover all or part of the front surface of the film including at least one photocured GRIN optical element. The protective layer can be a transparent layer. The protective layer can include polycarbonate (PC). The protective layer can include polyethylene terephthalate (PET) or triacetyl cellulose (TAC). The protective layer can include a substance having negligible birefringence. The protective layer can be impermeable to water. The protective layer can be scratch-resistant. The protective layer can have a base refractive index. The protective layer can provide some degree of UV protection. The protective layer can be adhered to the film including at least one photocured GRIN optical element using an adhesive.

[0123] In other embodiments of the present disclosure, the step of providing the layer may include the step of using a collimated LED / laser light source to photocure at least one region of the photocurable layer. A high-resolution 3D photocuring system, such as a two-photon confocal microscopy-based laser illumination system, may be used to photocure at least one region of the photocurable layer. The step of providing the layer may include the step of using a high-resolution photopolymerization process and the step of using a high-resolution intensity distribution type photomask (i.e., a chromium or resist-coated glass photomask used in projection lithography).

[0124] In other embodiments of the present disclosure, the layer may include a coating. The coating may be directly applied onto the lens surface or onto the lens substrate surface by various coating methods such as spray coating, spin coating, solution casting, liquid phase surface deposition, vapor phase surface deposition, etc. Before applying the coating to the lens surface or the lens substrate surface, the surface may be (pre)-treated, for example, using plasma treatment, to improve the bonding or adhesiveness with the coating layer.

[0125] An ophthalmic lens 1 (FIG. 1A) according to an embodiment of the present disclosure has an optical axis 2 and includes a layer 3 provided on the front surface of a substrate 5 (in this case, the substrate 5 forms part of the lens 1). The layer 3 has a uniform thickness and a uniform base refractive index. The layer 3 covers the front surface of the lens 1. Light from an on-axis distant point source passing through the region of the layer 3 having the base refractive index will be focused onto a spot 11 on the optical axis 2 of the lens 1. The spot 11 is on the base refractive power focal plane 13 shown in FIG. 1A.

[0126] As shown in FIGS. 1A and 1B, layer 3 includes a plurality of GRIN optical elements 7a, 7b disposed in concentric rings 9a, 9b (the dashed lines 9a, 9b are provided as guides for the eye and do not represent structural features of lens 1). Each of the GRIN optical elements 7a, 7b has a substantially cylindrical shape with an elliptical cross-section in a plane parallel to the surface of layer 3. Each of the GRIN optical elements 7a, 7b has a refractive index profile that varies in both the radial and lateral directions in a plane perpendicular to the cylindrical axis of the element 7a, 7b, i.e., in a plane parallel to the surface of layer 3. This results in an asymmetric refractive index profile across the entire element 7a, 7b. FIG. 1C is a top view of one of the GRIN optical elements 7a of lens 1 shown in FIGS. 1A and 1B, and FIG. 1D shows the same element 7a in perspective. The refractive index across the entire surface of element 7a varies in a plane perpendicular to the cylindrical axis of element 7a, radially (outwardly) from point "X" in a plane parallel to the front surface of layer 3, and also varies in the direction (laterally) indicated by arrow "Y" parallel to the front surface of layer 3. The refractive index profile is constant (i.e., does not vary) in the direction "Z" (see FIG. 1D) parallel to the cylindrical axis of the element 7a. As shown in FIG. 1E, the refractive index change has an asymmetric profile 22 in the direction "Y".

[0127] All of the GRIN elements 7a forming the inner ring 9a have the same refractive index profile (such as shown in FIGS. 1C and 1D) and are positioned at the same radial distance from the optical axis 2 of the lens 1. Since the GRIN optical elements 7a have an asymmetric refractive index profile as shown in FIGS. 1C to 1E, the local optical axes of the GRIN elements 7a are inclined with respect to the optical axis 2 of the lens 1. Light from an on-axis distant point source passing through the region of the layer 3 having the base refractive index is focused on the spot 11 on the optical axis. Light from an on-axis distant point source passing through the GRIN optical elements 7a is focused away from the optical axis 2 of the lens 1. The GRIN optical elements 7a are arranged on a ring 9a centered on the optical axis 2 of the lens 1, and light from an on-axis distant point source passing through the GRIN optical elements 7a forming the inner ring 9a will form a ring of foci 15a, 15b (shown in FIG. 1A). When the lens 1 is worn by a lens wearer, the GRIN elements 7a forming the inner ring 9a direct light from an on-axis distant point source toward an additional refractive power focal plane 17 closer to the rear surface of the lens 1 (i.e., farther from the retina or closer to the cornea) compared to the base refractive power focal plane 13 (shown in FIG. 1A). The local optical axis of each of the GRIN optical elements 7a intersects the optical axis of the lens, and the light rays from an on-axis distant point source passing through the GRIN optical elements 7a forming the inner ring 9a are directed (aimed) such that a small spot size of unfocused light is formed on the base refractive power focal plane 13. This can improve the quality of the image formed on the retina of the lens wearer.

[0128] All of the GRIN optical elements 7b forming the outer ring 9b have the same refractive index change (such as shown in FIGS. 1C and 1D) as the GRIN optical elements 7a forming the inner ring 9a. All of the GRIN optical elements 7b forming the outer ring 9b are positioned at the same radial distance from the optical axis 2 and at a greater radial distance from the optical axis 2 than the GRIN optical elements 7a forming the inner ring 9a.

[0129] The GRIN optical element 7b is disposed on a ring 9b centered on the optical axis 2 of the lens 1. They have a local optical axis that focuses light from an on-axis distant point source passing through the GRIN optical element 7b to form a ring of foci 19a, 19b (shown in FIG. 1A). The ring of foci 19a, 19b will have a larger radius than the ring of foci 15a, 15b formed from light passing through the inner ring 9a of the GRIN optical element 7a. The refractive index profile of the GRIN optical element 7b forming the outer ring 9b is the same as the refractive index profile of the GRIN optical element 7a forming the inner ring 9a. When the lens 1 is worn by a lens wearer, the GRIN element 7b forming the outer ring 9b will focus light toward the same additional refractive power focal plane 17 as the GRIN element 7a forming the inner ring 9a. Each local optical axis of the GRIN optical element 7b intersects the optical axis of the lens, and the light rays from an on-axis distant point source passing through the GRIN optical element 7b forming the outer ring 9b are directed (aimed) such that a small spot size of unfocused light is formed on the base refractive power focal plane 13. This can improve the quality of the image formed on the retina of the lens wearer.

[0130] An ophthalmic lens 101 (FIG. 2A) according to another embodiment of the present disclosure is centered on an optical axis 102 and includes a layer 103 provided on the front surface of a substrate 105 (in this case, the substrate 105 forms part of the lens 101). The layer 103 has a uniform base refractive index and a uniform thickness. The layer 103 covers the front surface of the lens 101. Light from an on-axis distant point source passing through the region of the layer 103 having the base refractive index will be focused to a spot 111 on the optical axis 102 of the lens 101. The spot 111 is on the base refractive power focal plane 113.

[0131] As shown in FIG. 2B, layer 103 includes a plurality of GRIN optical elements 107a, 107b disposed in concentric rings 109a, 109b (the dashed lines 109a, 109b are provided as guides to the eye and do not represent structural features of lens 101). Each of the GRIN optical elements 107a, 107b has a substantially cylindrical shape with an elliptical cross-section. Each of the GRIN optical elements 107a, 107b has a refractive index profile that varies in both the radial and lateral directions in a plane perpendicular to the cylindrical axis of the element 107a, 107b (i.e., in a plane parallel to the surface of layer 103). This results in an asymmetric refractive index profile across the entire element 107a, 107b as shown in FIGS. 2C through 2G. All of the GRIN elements 107a forming the inner ring 109a have the same refractive index change (as shown in FIGS. 2B, 2C, 2E, and 2G) and are positioned at the same radial distance from the optical axis 102. FIG. 2C is a top view of one of the GRIN optical elements 107a that is part of the inner ring 109a. FIG. 2E shows the same element 107a in perspective. The refractive index across the entire surface of element 107a in a plane perpendicular to the cylindrical axis of the element 107a varies radially (outwardly) from point "X" in a plane parallel to the front surface of layer 103 and also varies in the direction (laterally) indicated by arrow "Y" parallel to the front surface of layer 103. The refractive index profile is constant (i.e., does not change) in the direction "Z" parallel to the cylindrical axis of the element 107a as shown in FIG. 2E. As shown in FIG. 2G, the change in refractive index has an asymmetric profile 122a in the direction "Y".

[0132] All of these GRIN elements 107a have the same asymmetric refractive index profile and are positioned at the same radial distance from the optical axis 102, as shown in FIGS. 2C and 2E. Therefore, light from an on-axis distant point source passing through the GRIN optical element 107a will be focused away from the optical axis 102 to form a ring of foci 115a, 115b (shown in FIG. 2A). When the lens 101 is worn by a lens wearer, due to the refractive index profile of the GRIN optical element 107a, light from an on-axis distant point source is focused onto a low additional refractive power focal plane 117 closer to the rear surface of the lens 101 compared to the base refractive power focal plane 113.

[0133] FIG. 2D is a top view of one of the GRIN optical elements 107b that is part of the inner ring 109b. FIG. 2F shows the same element 107b in a perspective view. This element 107b has a different magnitude of refractive index change compared to the GRIN optical element 107a that forms part of the inner ring 109a. The refractive index across the entire surface of the element 107b in a plane perpendicular to the cylinder axis of the element 107b varies radially (radially outward) from point "X" in a plane parallel to the front surface of the layer 103 and also varies (laterally) in the direction indicated by arrow "Y" parallel to the front surface of the layer 103. The refractive index profile is constant (i.e., does not change) in the direction "Z" parallel to the cylinder axis of the element 107b, as shown in FIG. 2F. As shown in FIG. 2G, the refractive index change has an asymmetric profile 122b in the direction "Y".

[0134] All of the GRIN optical elements 107b that form the outer ring 109b also have the same refractive index change, but these elements 107b have a different refractive index profile from the GRIN optical elements 107a that form the inner ring 109a. All of the GRIN optical elements 107b that form the outer ring 109b are positioned at the same radial distance from the optical axis 102, but the radial distance from the optical axis 102 is greater than that of the GRIN optical elements 107a that form the inner ring 109a. The GRIN optical elements 107b that form the outer ring 109b have different focusing powers compared to the GRIN optical elements 107a that form the inner ring 109a. The local optical axis of the GRIN optical elements 107b that form part of the outer ring 109b is more inclined with respect to the optical axis 102 of the lens 101 compared to the local optical axis of the GRIN optical elements 107a that form part of the inner ring 109a. Light from an on-axis distant point source passing through the GRIN optical elements 107b that form the outer ring 109b is focused (condensed) to form rings of foci 119a, 119b as shown in FIG. 2A. The rings of foci 119a, 119b have a larger radius than the rings of foci 115a, 115b formed from the light passing through the inner ring 109a of the GRIN optical elements 107a, and the light passing through the GRIN optical elements 107b of the outer ring is focused (condensed) to an off-axis point on the high additional refractive power focal plane 123 that is closer to the rear surface of the lens 101 compared to the base refractive power focal plane 113 and closer to the rear surface of the lens 101 compared to the low additional refractive power focal plane 117.

[0135] An ophthalmic lens 201 (FIG. 3A) according to another embodiment of the present disclosure is centered on an optical axis 202 and includes a layer 203 provided on the front surface of a substrate 205 (in this case, the substrate 205 forms part of the lens 201). The base refractive power of the layer 203 is uniform, and the layer 203 has a uniform thickness. The layer 203 covers the front surface of the lens 201. Light from an on-axis distant point source passing through the region of the layer 203 having the base refractive index will be focused to a spot 211 on the optical axis 202 of the lens 201. The spot 211 is on the base refractive power focal plane 213 shown in FIG. 3A.

[0136] Figure 3B shows a schematic top view of the lens 201 of FIG. 3A. The layer 203 includes a plurality of GRIN optical elements 207 arranged in a random pattern throughout the layer 203. The GRIN optical elements 207 have a circular cross-section in the plane of the layer 203 and have an asymmetric refractive index profile that varies continuously in the circumferential direction (the direction of arrow "W" shown in FIGS. 3C and 3D) and the radial direction. The asymmetric refractive index change of the element 207 in the "W" direction is shown by curve 222 in FIG. 3D. All of the GRIN elements 207 have the same refractive index change, but are positioned at different radial distances from the optical axis 202, as shown in FIGS. 3C and 3D. Since the GRIN element 207 has an asymmetric refractive index profile, light passing through the GRIN optical element 207 from an off-axis distant point source will be focused away from the optical axis 202. When the lens 201 is worn by a lens wearer, the GRIN optical element 207 focuses light toward an off-axis focus on an additional refractive power focal plane 217 that is closer to the rear surface of the lens 201 compared to the base refractive power focal plane 213, as shown in FIG. 3A.

[0137] Figure 3C is a top view of the GRIN optical element 207 of the lens 201 shown in FIGS. 3A and 3B. The GRIN optical element 207 has a circular cross-section and has an asymmetric refractive index profile that varies in the circumferential direction shown by arrow "W" and the radial direction. The refractive index profile in the "W" direction along the dashed curve shown in FIG. 3C is plotted as curve 222 in FIG. 3D.

[0138] FIG. 4 is a front view of glasses 325 including lenses 301 similar to lens 101 shown in FIGS. 2A and 2B. The glasses 325 include two lenses 301. Each lens 301 is centered on an optical axis 302 and includes a layer 303 provided on a front surface of a substrate (in this case, the substrate forming part of the lens 301). The base refractive index of the layer 303 is uniform, and the layer 303 has a uniform thickness. The layer 303 covers the front surface of the lens 301. Light from an on-axis far point source passing through the base layer 303 of the lens 301 will be focused to a spot on the optical axis 302 of the lens 301 at a base refractive power focal plane (not shown).

[0139] Each layer 303 includes a plurality of GRIN optical elements 307a, 307b arranged in concentric rings 309a, 309b (the dashed lines are provided as a guide to the eye and do not represent structural features of the lens 301). Each of the GRIN optical elements 307a, 307b has a refractive index profile that varies in both the radial and lateral directions across the entirety of the element 307a, 307b parallel to the plane of the layer 303. It results in an asymmetric profile. All of the GRIN elements 307a forming the inner ring 309a have the same refractive index change and are positioned at the same radial distance from the optical axis 302. Since the GRIN element 307a has an asymmetric refractive index profile, light passing through the GRIN optical element 307a from an on-axis far point source will be focused away from the optical axis 302. The GRIN optical elements 307a are arranged in a circular shape centered on the optical axis 302 of each lens 301, and light from a far point source passing through the GRIN optical elements 307a forming the inner ring 309a will form a ring of foci.

[0140] All of the GRIN optical elements 307b that form the outer ring 309b also have the same refractive index change, but these elements 307b have a different refractive index change from the GRIN optical elements 307a that form the inner ring 309a. All of the GRIN optical elements 307b that form the outer ring 309b are positioned at the same radial distance from the optical axis 302, but the radial distance from the optical axis 302 is greater than that of the GRIN optical elements 307a that form the inner ring 309a. Light from an on-axis distant point source passing through the GRIN optical elements 307b that form the outer ring 309b will form a ring of foci. This ring of foci will have a larger radius than the ring of foci formed from the light passing through the inner ring 309a of the GRIN optical element 307a. The refractive index profile of the GRIN optical elements 307b that form the outer ring 309b is different from the refractive index profile of the GRIN optical elements 307a that form the inner ring 309a. When the lens 301 is worn by a lens wearer, the light passing through the GRIN optical elements 307a that form the inner ring 309a is focused on a plurality of points on the first focal plane, and the light passing through the GRIN optical elements 307b that form the outer ring 309b will be focused on a plurality of points on a different second focal plane. When the lens 301 is worn by a lens wearer, both the first focal plane and the second focal plane will be closer to the rear surface of the lens than the base refractive power focal plane.

[0141] FIG. 5A shows a schematic top view of a film 403 used in an ophthalmic lens according to an embodiment of the present disclosure. The film 403 includes a Bayfol® HX film, 500 mm 3It is cut into a circular shape having an area. The film has a base refractive index and a certain thickness. The film 403 is formed by a photocuring method and includes a plurality of GRIN optical elements 407 randomly distributed across the film 403. Each GRIN optical element 407 has a circular cross-section in the plane of the film and has a refractive index profile that varies asymmetrically in the circumferential direction. Some of the GRIN optical elements 407 have different asymmetric refractive index profiles. FIG. 5B shows a cross-sectional view of a small portion of the film 403 of FIG. 5A applied to the substrate 405 in the form of a contact lens 401. The GRIN optical elements 407 extend through the thickness of the film 403. The lens 401 is centered on the optical axis 402 that extends in a direction substantially perpendicular to the plane of the film 403. Light from an on-axis distant point source passing through a portion of the film 403 having a base refractive index will be focused on a spot on the optical axis 402. Since the GRIN optical elements 407 have an asymmetric refractive index profile, the local optical axis of each GRIN optical element 407 is inclined with respect to the optical axis 402 of the lens 401. As a result, light from an on-axis distant point source passing through each GRIN element 407 will be focused on an off-axis focus. When different GRIN optical elements 407 have different asymmetric refractive index profiles, the local optical axes of the elements 407 can be inclined by different amounts, and the plurality of GRIN optical elements 407 can have different focusing powers.

[0142] FIG. 6 is a flowchart showing a method 500 for manufacturing an ophthalmic lens according to an embodiment of the present disclosure. In a first step 531, an ophthalmic lens centered on the optical axis is provided. In a second step 533, a layer including a plurality of GRIN optical elements having an asymmetric refractive index profile is provided. In a third step 535, the method includes applying the layer to the front surface of the lens. When the film is provided on the surface of the lens, light from an on-axis distant point source passing through the layer is focused on a spot on the optical axis of the lens. Light from an on-axis distant point source passing through the GRIN optical elements will be focused on a plurality of off-axis foci.

[0143] Although the present disclosure has been described and illustrated with reference to specific exemplary embodiments, it will be understood by those skilled in the art that the present disclosure can be useful in many different variations not particularly illustrated herein. By way of example only, certain possible variations are described.

[0144] In the foregoing exemplary embodiments of the present disclosure, each GRIN element has a refractive index profile that provides a focusing power higher than the base refractive index of the lens. In other exemplary embodiments, the GRIN element can have a refractive index profile that provides a focusing power lower than the base refractive index of the lens.

[0145] In the foregoing exemplary embodiments, the layer is applied to the surface of the lens. In other embodiments, the layer can be applied to a substrate, and then the substrate can be applied to the surface of the lens.

[0146] In the foregoing description, integers or elements having known obvious or predictable equivalents have been referred to, and such equivalents are incorporated herein as if individually described herein. To determine the true scope of the present disclosure, reference should be made to the claims. The claims should be construed to include any such equivalents. It will also be understood by the reader that the integers or features of the present disclosure described as being advantageous or convenient or the like are optional and do not limit the scope of the independent claims. Furthermore, such optional integers or features may be beneficial in some embodiments of the present disclosure, but may not be desirable in other embodiments, and thus may not be present in other embodiments.

Claims

**Claim 1** An ophthalmic lens having an optical axis, comprising a layer provided on the surface of a substrate, the layer having a base refractive index and including at least one refractive index distribution type optical element having an asymmetric refractive index profile, the at least one refractive index distribution type optical element being adapted to condense light from a distant point light source on the optical axis to a point at a first distance from the optical axis characterized ophthalmic lens. **Claim 2** The layer includes a plurality of the refractive index distribution type optical elements randomly distributed across the layer characterized ophthalmic lens according to claim 1. **Claim 3** The layer includes a plurality of the refractive index distribution type optical elements arranged to form at least one annular ring characterized ophthalmic lens according to claim 1. **Claim 4** At least two of the refractive index distribution type optical elements have the same asymmetric refractive index profile and condense light toward the same focal plane characterized ophthalmic lens according to claim 1. **Claim 5** At least two of the refractive index distribution type optical elements have different asymmetric refractive index profiles, a first refractive index distribution type optical element condenses light from an on-axis distant point light source toward a spot at a first distance from the optical axis of the lens, a second refractive index distribution type optical element condenses light from an on-axis distant point light source toward a spot at a different second distance from the optical axis of the lens characterized ophthalmic lens according to any one of claims 1 to 4. **Claim 6** A plurality of refractive index distribution type optical elements positioned at the same radial distance from the optical axis of the lens have the same refractive index profile characterized ophthalmic lens according to any one of claims 1 to 5. **Claim 7** A plurality of refractive index distribution type optical elements forming a first annular ring at a first radial distance from the optical axis of the lens have a first refractive index profile, a plurality of refractive index distribution type optical elements forming a second concentric annular ring at a greater radial distance from the optical axis of the lens have a different second refractive index profile characterized ophthalmic lens according to claim 6. **Claim 8** A plurality of refractive index distribution type optical elements positioned at a greater radial distance from the optical axis of the lens have a refractive index profile that provides a greater focusing power than a plurality of refractive index distribution type optical elements positioned at a smaller radial distance from the optical axis of the lens The ophthalmic lens according to claim 6 or 7, characterized in that...

9. The layer is provided on the front surface of the substrate The ophthalmic lens according to any one of claims 1 to 8, characterized in that...

10. The layer is a film applied to the surface of the substrate The ophthalmic lens according to any one of claims 1 to 9, characterized in that...

11. The layer is a coating provided on the surface of the substrate The ophthalmic lens according to any one of claims 1 to 10, characterized in that...

12. The substrate is a thin film for application to the surface of the lens The ophthalmic lens according to any one of claims 1 to 11, characterized in that...

13. The substrate is the lens The ophthalmic lens according to any one of claims 1 to 12, characterized in that...

14. The lens is an eyeglass lens The ophthalmic lens according to any one of claims 1 to 13, characterized in that...

15. The lens is a contact lens The ophthalmic lens according to any one of claims 1 to 13, characterized in that...

16. The lens is a rigid contact lens The ophthalmic lens according to any one of claims 1 to 13, characterized in that...

17. The layer is a photopolymer layer, and each of the at least one refractive index distribution type optical element is a photocured refractive index distribution type optical element The ophthalmic lens according to any one of claims 1 to 16, characterized in that...

18. Each of the at least one refractive index distribution type optical element has a refractive index profile defined by an asymmetric polynomial function The ophthalmic lens according to any one of claims 1 to 17, characterized in that...

19. Each of the at least one refractive index distribution type optical element has a diameter or width of 1 μm to 5 mm The ophthalmic lens according to any one of claims 1 to 18, characterized in that...

20. A plurality of refractive index distribution type optical elements occupy 20% to 80% of the surface area of the layer The ophthalmic lens according to any one of claims 1 to 19, characterized in that...

21. The light from an on-axis point light source passing through the layer is focused on the focus on the optical axis of the lens at the base refractive power focal plane, Any or all of the refractive index distribution type optical elements are configured such that light from an off-axis distant point light source passing through those GRIN optical elements forms light having a small spot size centered on the optical axis of the lens at the base refractive power focal plane. The ophthalmic lens according to any one of claims 1 to 20, characterized by the above.

22. A film used as the layer of the ophthalmic lens according to any one of claims 1 to 21, The film has a base refractive index, The film includes at least one refractive index distribution type optical element having an asymmetric refractive index profile. A film characterized by the above.

23. A method for manufacturing an ophthalmic lens according to any one of claims 1 to 21, A step of providing a lens having an optical axis, A step of providing a layer having a base refractive index, the layer including at least one refractive index distribution type optical element having an asymmetric refractive index profile, A step of applying the layer to the surface of the lens substrate, the at least one refractive index distribution type optical element being configured to condense light from an off-axis distant point light source to a point at a first distance from the optical axis. A method characterized by including the above steps.

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