Contact lens including a diffractive optical element and related methods

Abstract

Provided is an improved contact lens including a diffractive optical element. **Solution**: The present disclosure relates to a contact lens (100) including a diffractive optical element (101), an optical filter (103), and an optical axis (109) passing through the optical filter and the diffractive optical element. The diffractive optical element (101) is configured to focus visible light. The optical filter (103) is configured to filter light having a wavelength from 450 nm to 495 nm. The optical filter (103) can pass light having a wavelength from 500 nm to 750 nm. The optical filter (103) can include one or more colorants. Further, the present disclosure relates to a method (600) for manufacturing a contact lens. Further, the present disclosure relates to a method (700) for correcting a user's eyesight.

Description

Technical Field

[0001] The present disclosure relates to contact lenses. More particularly, although not limited thereto, the present disclosure relates to a contact lens including a diffractive optical element configured to focus visible light and an optical filter configured to filter light having a wavelength from 450 nm to 495 nm.

Background Art

[0002] Eyeglass lenses that utilize refraction to focus visible light onto a user's retina are well known. Also, diffractive optical elements are used to focus light, instead of or in addition to utilizing refraction.

[0003] Diffractive optical elements interact with light by diffracting the light at the interface of two or more materials, each having a different refractive index from one another. Some diffractive optical elements have a diffractive structure made in an annular region arranged to focus incident light onto one or more focal points.

[0004] Lenses that include diffractive optical elements will have much greater chromatic aberration than refractive lenses of the same refractive power. The focal refractive power (in diopters) of a diffractive optical element varies directly proportional to the wavelength. The focal refractive power is the reciprocal of the focal length, and thus the distance at which light is focused from the lens varies inversely proportional to the wavelength. This means that for a particular annular region of a diffractive optical element, light of a shorter wavelength will be focused further from the lens than light of a longer wavelength. This relationship causes longitudinal chromatic aberration. In use, due to chromatic aberration, a user of an eyeglass lens that includes a diffractive optical element will consequently experience a polychromatic blurred halo around the image. This degrades the quality of the user's vision.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present disclosure seeks to mitigate the above problems. Alternatively or additionally, the present disclosure seeks to provide an improved contact lens including a diffractive optical element. **Means for Solving the Problems**

[0006] A first aspect of the present disclosure relates to a contact lens including a diffractive optical element, an optical filter, and an optical axis passing through the optical filter and the diffractive optical element, wherein the diffractive optical element is configured to focus visible light, and the optical filter is configured to filter light having a wavelength from 450 nm to 495 nm.

[0007] A second aspect of the present disclosure relates to a method for manufacturing a contact lens, the method including obtaining one or more colorants that absorb light having a wavelength from 450 nm to 495 nm and allow light having a wavelength from 500 nm to 750 nm to pass through, forming a diffractive optical element having a diffractive structure configured to focus visible light having a wavelength greater than 495 nm, and forming a contact lens incorporating the diffractive optical element and the one or more colorants.

[0008] A third aspect of the present disclosure relates to a method for correcting a user's vision, the method including obtaining a contact lens according to the present disclosure and placing the contact lens on the surface of the user's eye, wherein the contact lens diffracts light so that the light is focused on the retina of the user's eye.

[0009] Preferred but optional features of the present disclosure are set forth below and in the dependent claims.

[0010] It should be recognized that the features described in connection with one aspect of the present disclosure can be incorporated into other aspects of the present disclosure. For example, the methods of the present disclosure can incorporate any of the features described with reference to the apparatus of the present disclosure, and vice versa.

[0011] Hereinafter, exemplary embodiments will be described with reference to the attached schematic drawings for illustrative purposes only.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Modes for Carrying Out the Invention

[0013] According to a first aspect of the present disclosure, a contact lens includes a diffractive optical element, an optical filter, and an optical axis passing through the optical filter and the diffractive optical element. The diffractive optical element is configured to focus visible light. The optical filter is configured to filter light having a wavelength from 450 nm to 495 nm.

[0014] As used herein, the term "contact lens" is used to refer to an ophthalmic lens that can generally be placed on a human eye in the art. It should be recognized that such a contact lens is clinically acceptable and movable on the eye and does not adhere to the human eye(s).

[0015] The contact lens has a single diffractive optical element.

[0016] The contact lens can be for correcting or improving eyesight related to myopia, presbyopia, hyperopia, astigmatism, or another refractive anomaly.

[0017] The optical filter can pass or transmit light with a wavelength from 500 nm to 750 nm. The optical filter can pass light with a wavelength from 496 nm to 750 nm. The optical filter can pass light with a wavelength greater than 500 nm. The optical filter can pass light with a wavelength greater than 495 nm.

[0018] The optical filter can include one or more colorants. One or more of the colorants can be a dye. One or more of the colorants can be a pigment. One or more of the colorants can be a polymerizable dye. One or more of the colorants can be an anthraquinone dye. One or more of the colorants can be configured to filter light with a wavelength from 450 nm to 495 nm. One or more of the colorants can be configured to filter light with a wavelength from 400 nm to 495 nm. A combination of two or more colorants can be configured to filter light with a wavelength from 400 nm to 495 nm. A combination of two or more colorants can be configured to filter light with a wavelength from 450 nm to 495 nm.

[0019] The optical filter can contain one or more compounds. One or more of the compounds can be configured to filter ultraviolet light. One or more of the compounds can be configured to filter light that is harmful to the human eye. One or more of the compounds can absorb light having a wavelength from 100 nm to 400 nm. One or more of the compounds can absorb light having a wavelength from 400 nm to 450 nm. One or more of the compounds can absorb light having a wavelength from 100 nm to 450 nm. One or more of the compounds can absorb light having a wavelength from 100 nm to 495 nm. A combination of two or more compounds can be configured to filter light having a wavelength from 100 nm to 495 nm. The optical filter can absorb wavelengths that may be harmful to the human eye. The optical filter can contain at least one compound that absorbs UV light. Those skilled in the art will recognize suitable UV-blocking compounds. The UV-blocking compound can be colorless.

[0020] The contact lens can contain a material in which one or more colorants are dispersed. The contact lens can contain a material in which one or more colorants and one or more compounds are dispersed. The contact lens can contain a polymer material. The contact lens can contain a polymer material in which one or more colorants are dispersed. The contact lens can contain a polymer material in which one or more colorants and one or more compounds are dispersed. One or more of the colorants can be a polymerizable dye. The contact lens can contain a polymer matrix formed from one or more monomers and one or more colorants.

[0021] The optical filter can contain a first colorant having an absorption maximum wavelength in the range of 450 nm to 495 nm and a second colorant having an absorption maximum wavelength in the range of 450 nm to 495 nm. The first colorant can have a different absorption maximum wavelength compared to the second colorant.

[0022] As used herein, the term "absorption peak wavelength" is defined as the wavelength at which the colorant has the highest absorbance measured by ultraviolet-visible spectroscopy. This is also known as the characteristic wavelength of the colorant.

[0023] The characteristic wavelength of the diffractive optical element can be from 500 nm to 750 nm. The characteristic wavelength of the diffractive optical element is defined as the wavelength at which the diffractive optical element is designed to have a preset focal length.

[0024] The optical axis of the lens is defined with reference to a distant point light source. Light from a distant point light source on the optical axis of the lens (hereinafter referred to as an on-axis distant point light source) will be focused on the optical axis of the lens.

[0025] The optical region is centered on the optical axis. The optical axis can coincide with the center of the contact lens. The optical region is composed of the part of the contact lens that has an optical function during use. The optical region can be configured to be positioned above or in front of the pupil of the eye during use. In a plan view, the contact lens can have an optical region surrounded by a peripheral region. The peripheral region is not part of the optical region and is located outside the optical region. The peripheral region can be located above the iris when the contact lens is worn. The peripheral region provides a mechanical function, for example, it can increase the size of the contact lens, as a result, facilitating the handling of the contact lens. The peripheral region can extend to the edge of the contact lens. The peripheral region can provide a ballast for preventing the rotation of the contact lens and / or a shape region for improving the comfort of the contact lens wearer.

[0026] The contact lens can have a circular shape. The contact lens can have an oval shape. The contact lens can have an elliptical shape. The contact lens can have a diameter ranging from 10 mm to 20 mm. The contact lens can have an optical region with a diameter ranging from 7 mm to 10 mm. The contact lens can have a convex front surface. The contact lens can have a concave rear surface. The optical region can be circular in shape. The optical region can be oval in shape. The optical region can be elliptical in shape.

[0027] The diffractive optical element can be centered on the optical axis of the contact lens. In a plan view, the diffractive optical element can be surrounded in the peripheral region of the contact lens. The diffractive optical element can be located within the optical region of the contact lens. The diffractive optical element can define the optical region of the contact lens.

[0028] In a cross-section including the optical axis, the diffractive optical element can include a series of ridges and valleys of a first refractive index filled with a material having a second refractive index. The diffractive optical element can include two or more materials each having a different refractive index from one another.

[0029] The diffractive optical element can include a first portion having a first refractive index and a second portion including a liquid crystal cell that can be switched between a matching state and a non-matching state. In the matching state, the refractive index of the liquid crystal cell may be the same as the first refractive index. In the non-matching state, the refractive index of the liquid crystal cell may be different from the first refractive index. In the non-matching state, the refractive index of the liquid crystal cell may be greater than the refractive index of the liquid crystal cell in the matching state. In the non-matching state, the refractive index of the liquid crystal cell may be less than the refractive index of the liquid crystal cell in the matching state. The liquid crystal cell can be electrically switchable.

[0030] In a cross-section passing through the optical axis, the first portion of the diffractive optical element can include a series of ridges and valleys. The ridges and valleys of the first portion can abut against the liquid crystal cell of the second portion. The liquid crystal can be switchable between a matching state in which its refractive index is the same as the first refractive index of the first portion and a non-matching state in which its refractive index is different from the first refractive index of the first portion.

[0031] In a cross-section including the optical axis, the diffractive optical element can include a series of ridges and valleys on its front surface surrounded by the material of the contact lens. The material of the contact lens can have a refractive index different from that of the diffractive optical element. The boundary between the diffractive optical element and the material of the contact lens can define the diffractive structure of the diffractive optical element.

[0032] The diffractive optical element can have a radially varying refractive index, i.e., the refractive index can vary radially outward from the optical axis. The diffractive optical element can have an axially varying refractive index, i.e., the refractive index can vary in the direction of the optical axis. The diffractive optical element can have a refractive index that varies sinusoidally in the axial direction. The diffractive optical element can have a refractive index that varies sinusoidally in the radial direction. The diffractive optical element can have a refractive index that varies linearly in the radial direction. The diffractive optical element can have a refractive index that varies linearly in the axial direction. The diffractive optical element can have a refractive index that increases in the radial direction. The diffractive optical element can have a refractive index that decreases in the radial direction. The diffractive optical element can have a refractive index that increases in the axial direction. The diffractive optical element can have a refractive index that decreases in the axial direction. The refractive index of the diffractive optical element can be uniform.

[0033] In a plan view, the diffractive optical element can comprise concentric annular regions. The concentric annular regions can be centered around the optical axis of the contact lens. Each pair of peaks can define an annular region. Each concentric annular region can define an annular diffractive region.

[0034] The diffractive optical element can be embedded within the contact lens. The contact lens can include a lens body. The diffractive optical element can be embedded within the lens body. The diffractive optical element can have a refractive index different from that of the lens body. The refractive index of the lens body can be uniform. For example, the first portion of the diffractive optical element can have a refractive index of 1.48, and the second portion of the diffractive optical element can be a liquid crystal cell whose refractive index can be switched between 1.48 and 1.7.

[0035] The diffractive optical element can include a diffractive structure that diffracts and refracts the light incident thereon.

[0036] The contact lens can include a layer containing an optical filter. The layer can form the front surface of the contact lens. This layer can form the rear surface of the contact lens. The contact lens can further include a lens body joined to the layer containing the optical filter. The layer can have a thickness smaller than that of the lens body. The layer can cover the entire front surface of the lens body. The layer can cover the entire rear surface of the lens body. The layer can cover a part of the front surface of the lens body. The layer can cover a part of the rear surface of the lens body. The layer can cover the central portion of the front or rear surface of the lens body, for example, the portion located in front of the diffractive optical element, and light needs to pass through the layer in order for the diffractive optical element to diffract it. There may be a peripheral region of the contact lens that is not covered by the layer.

[0037] The contact lens can be a soft contact lens. The contact lens can include a silicone hydrogel material. The contact lens can be a rigid gas permeable contact lens. The contact lens can be a toric contact lens. For example, the toric contact lens can include an optical region shaped to correct human astigmatism. The contact lens can be a daily disposable lens. The contact lens can be a continuous wear contact lens.

[0038] Contact lenses can include an elastomer material, a silicone elastomer material, a hydrogel material, a silicone hydrogel material, or combinations thereof. As understood in the contact lens art, a hydrogel is a material that retains moisture in an equilibrium state and is free of silicone-containing chemicals. A silicone hydrogel is a hydrogel that includes a silicone-containing chemical. Hydrogel materials and silicone hydrogel materials have an equilibrium water content (EWC) of at least about 10% to about 90% (wt / wt), as described in connection with the present disclosure. In some embodiments, the hydrogel material or the silicone hydrogel material has an EWC of about 30% to about 70% (wt / wt). In comparison, silicone elastomer materials as described in connection with the present disclosure have a water content of about 0% to less than 10% (wt / wt). Typically, the silicone elastomer materials used in the methods or devices of the present invention have a water content of 0.1% to 3% (wt / wt). Examples of suitable lens formulations include the following United States Adopted Names (USAN), namely, Metafilcon A, Ocufilcon A, Ocufilcon B, Ocufilcon C, Ocufilcon D, Omafilcon A, Omafilcon B, Confilcon 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, Rioxofilcon A, Derefilcon A, Verofilcon A, Califilcon A, Refilcon A, and the like.

[0039] Alternatively, the contact lens can comprise, consist essentially of, or consist of a silicone elastomer material. For example, the contact lens can comprise, consist essentially of, or consist of a silicone elastomer material having a Shore A hardness of from 3 to 50. The Shore A hardness can be determined using conventional methods (e.g., using the method of DIN 53505), as will be understood by those skilled in the art. Other silicone elastomer materials can be obtained, for example, from NuSil Technology or Dow Chemical Company.

[0040] According to a second aspect, the present disclosure provides a method of manufacturing a contact lens. The method includes obtaining one or more colorants that absorb light having a wavelength from 450 nm to 495 nm and that allow light having a wavelength from 500 nm to 750 nm to pass through. The method includes forming a diffractive optical element having a diffractive structure configured to focus visible light having a wavelength higher than 495 nm. The method includes forming a contact lens that includes the diffractive optical element and one or more colorants.

[0041] Also, the method includes obtaining one or more compounds that absorb UV light. Also, the step of forming the contact lens includes incorporating the one or more compounds into the contact lens. Also, the step of forming the contact lens can include molding a lens body around the diffractive optical element, and the diffractive optical element is configured to be embedded in the lens body. Also, the step of forming the contact lens can include forming a layer incorporating one or more colorants. Also, the step of forming the contact lens can include bonding the rear surface of the layer to the front surface of the lens body. Also, the method can include applying an adhesive to the rear surface of the layer. Also, the method can include applying the adhesive to the front surface of the lens body. The adhesive can be a transparent adhesive.

[0042] According to a third aspect, the present disclosure provides a method for correcting a user's vision. The method includes obtaining a contact lens according to the present disclosure. The method includes placing the contact lens on the surface of the user's eye. The method includes the contact lens diffracting light such that the light is focused on the retina of the user's eye.

[0043] The contact lens can be a molded contact lens. The contact lens can be formed, for example, by an injection molding process, a spin casting process, a lathe process, or a combination thereof. As will be understood by those skilled in the art, the injection molding process refers to the molding of a lens by placing a lens molding material between a female member having a concave lens member molding surface and a male member having a convex lens member molding surface.

[0044] In FIG. 1, the contact lens 100 has a contact lens body 105 formed from a silicone hydrogel material. The contact lens 100 includes a diffractive optical element 101 and an optical filter 103. The optical filter 103 is formed from a mixture of colorants that together filter light having a wavelength from 450 nm to 495 nm. Further, the optical filter 103 absorbs ultraviolet wavelengths that are harmful to the human eye. The optical filter 103 allows light having a wavelength from 500 nm to 750 nm to pass through. The diffractive optical element 101 is centered on the optical axis 109 of the contact lens 100 and extends in a direction perpendicular to the optical axis. In a plan view, the diffractive optical element 101 is radially surrounded by a peripheral region 102 of the contact lens 100. The optical filter 103 is a mixture of colorants dispersed in the material of the lens body 105 shown as a shaded area covered with small dots in the drawing. The diffractive optical element 101 is embedded within the lens body 105 and is surrounded by the lens body 105 everywhere. In a plan view (FIG. 1), the diffractive optical element 101 includes a series of concentric annular regions 111.

[0045] In FIG. 2, the diffractive optical element 101 of the contact lens 100 includes a first portion 104 having a first refractive index and a second portion 106 having a liquid crystal cell that can be electrically switched between a matching state and a non-matching state. In the matching state, the liquid crystal cell has the same refractive index as the first refractive index. In the non-matching state, the liquid crystal cell is “switched” so that the liquid crystal cell has a refractive index greater than the first refractive index. In the cross section shown in FIG. 2, the first portion 104 of the diffractive optical element 101 has a series of peaks extending outward from the optical axis 109 of the contact lens 100 toward the peripheral portion 107 of the contact lens. The second portion 106 has a corresponding shape so as to coincide with the first portion 104 and a continuous boundary is generated therebetween. When the second portion 106 is in the matching state, the second portion 106 has the same refractive index as the first portion 104. When the second portion 106 is in the non-matching state, the second portion 106 has a refractive index greater than the refractive index of the first portion 104.

[0046] In FIG. 3, the prior art contact lens 200 includes a diffractive optical element 201. Since the contact lens 200 does not include an optical filter that blocks light having a wavelength from 450 nm to 495 nm, all wavelength ranges of visible light can pass through the contact lens 200 and be incident on the diffractive optical element 201.

[0047] FIG. 3 shows a pair of light rays 220 incident on the prior art contact lens 200. The diffractive optical element 201 diffracts the incident light. The refractive power of the diffractive optical element is given by the following equation. P = 2mλ / r^2 P is the refractive power (diopter), λ is the wavelength (meter), and r is the radius (meter) of the m-th annular diffraction region. The refractive power of a predetermined annular diffraction region of the diffractive optical element varies with the wavelength. This relationship causes chromatic aberration.

[0048] The diffractive optical element 201 has a characteristic wavelength of 600 nm. The diffractive optical element is designed to accurately focus light having the characteristic wavelength at the target focus 210. The target focus of the contact lens is determined during manufacturing. Light having a wavelength shorter than the characteristic wavelength focuses at a position slightly farther from the contact lens than the target focus 210. Light having a wavelength longer than the characteristic wavelength focuses at a position slightly closer to the contact lens than the target focus 210. FIG. 3 shows a pair of light rays 220 incident on the diffractive optical element 201. The optical axis 212 passes through the center of the diffractive optical element 201. The target focus 210 is on this axis. The light ray 204 corresponding to red light has a wavelength longer than the characteristic wavelength and focuses at a position closer to the contact lens 200 than the target focus 210. The light ray 208 corresponding to blue light has a wavelength shorter than the characteristic wavelength and focuses at a position farther from the contact lens 200 than the target focus 210. The light ray 206 corresponding to green light focuses at the position closest to the target focus 210 and between them. The difference in focal length between the longer wavelength light ray 204 and the shorter wavelength light ray 208 is indicated by the dashed arrow 213.

[0049] When considering the diffractive optical element alone, the first diffractive region of the diffractive optical element 201 with a diameter of 0.5 mm has a refractive power of 4.8 diopters at a wavelength of 600 nm. At 450 nm, the refractive power of the first diffractive region is 3.6 diopters. At 750 nm, the refractive power of the first diffractive region is 6.0 diopters. Thereby, a range of refractive power of 2.4 diopters is obtained. Since the refractive power is the reciprocal of the focal length, the focal length changes from 0.28 m to 0.17 m, which gives a chromatic aberration of 0.11 m.

[0050] In FIG. 4, the contact lens 100 according to the present embodiment of the present disclosure includes a diffractive optical element 101 that diffracts light incident on the contact lens 100. The contact lens 100 includes an optical filter 103 that filters light having a wavelength from 450 nm to 495 nm. Visible light having a wavelength from 496 nm to 750 nm can pass through the contact lens 100 and can be diffracted by the diffractive optical element 101. The diffractive optical element 101 has a characteristic wavelength of 600 nm. The diffractive optical element is designed to accurately focus light having the characteristic wavelength on the target focus 310 on the optical axis 109. The pair of light rays 320 pass through the optical filter 103 and are incident on the diffractive optical element 101. The light ray 304 corresponding to red light having a wavelength longer than the characteristic wavelength is focused at a position closer to the contact lens 100 than the target focus 310. The light ray 306 corresponding to a shorter wavelength of visible light up to at least 496 nm is focused at a position farther from the contact lens 100 than the target focus 310. The difference in focal length between the longer wavelength light ray 304 and the shorter wavelength light ray 306 is indicated by the dashed arrow 313.

[0051] When considering the diffractive optical element alone, the first diffractive region of the diffractive optical element 101 having a diameter of 0.5 mm has a refractive power of 4.8 diopters at a wavelength of 600 nm. At 500 nm, the refractive power of the first diffractive region is 4.0 diopters. At 750 nm, the refractive power of the first diffractive region is 6.0 diopters. Thereby, a refractive power range of 2.0 diopters is obtained. Since the refractive power is the reciprocal of the focal length, the focal length changes from 0.25 m to 0.17 m, which gives a chromatic aberration of 0.08 m.

[0052] A comparison of FIG. 4 and FIG. 3 shows how the use of the optical filter 103 that blocks light with wavelengths from 450 nm to 495 nm reduces the visible light spectrum that can pass through the contact lens 100, and thus reduces the refractive power range of the diffractive optical element 101. By reducing the refractive power range, the chromatic aberration generated by the diffractive optical element is reduced, and the blur around the focus is reduced. As a result, a sharper and clearer image is presented to the user of the contact lens.

[0053] Hereinafter, a second embodiment of the present disclosure will be described. In FIG. 5, the contact lens 400 includes a diffractive optical element 401 and has other features similar to those described in connection with the first embodiment. Hereinafter, the differences will be described. The contact lens 400 includes a lens body 405 and a layer 408 including an optical filter 403. The diffractive optical element 401 is embedded in the material of the lens body 405 and coincides with the optical axis 409. In the layer 408, a mixture of colorants that together filter light with wavelengths from 450 nm to 495 nm is scattered. Also, the optical filter 403 absorbs ultraviolet wavelengths that are harmful to the human eye. The layer 408 is joined to the front surface 410 of the lens body 405 and covers the entire front surface 410 up to the peripheral edge of the contact lens 407. The layer 408 including the optical filter 403 allows light with wavelengths from 500 nm to 750 nm to pass through the layer 408 and be diffracted by the diffractive optical element 401.

[0054] The diffractive optical element 401 has a first portion 404 and a second portion 406. The first portion 404 has a first refractive index. The second portion 406 is a liquid crystal cell that can be switched between a matching state and a non-matching state. In the matching state, the second portion 406 has the same refractive index as the first refractive index. In the non-matching state shown in FIG. 5, the second portion 406 has a second refractive index that is greater than the first refractive index. In the cross-sectional view shown in FIG. 5, the first portion 404 of the diffractive optical element 401 has a series of peaks that extend outward from the optical axis 409 of the contact lens toward the peripheral portion 407. The second portion 406 surrounds the peaks of the first portion 404 of the diffractive optical element 401. There is a continuous boundary between the material of the first portion 404 of the diffractive optical element 401 and the second portion 406 of the diffractive optical element 401. In a plan view (not shown), the diffractive optical element includes a series of concentric annular regions. When the second portion 406 of the diffractive optical element 401 is switched to the non-matching state and thus has a refractive index different from that of the first portion 404, each annular region is a diffractive region defined by a pair of peaks of the diffractive optical element.

[0055] The third embodiment of the present disclosure is slightly different from the second embodiment. Hereinafter, the differences will be described. In FIG. 6, the contact lens 500 includes a diffractive optical element 501, a lens body 505, a first layer 508a, and a second layer 508b. In the first layer 508a, a mixture of compounds that together filter out ultraviolet wavelengths harmful to the human eye is dispersed. The first layer 508a is bonded to the front surface 510 of the lens body 505 and covers the entire front surface 510 up to the peripheral portion 507 of the contact lens 500. In the second layer 508b, a mixture of colorants that together filter out light having a wavelength of 450 nm to 495 nm is dispersed. Both the first layer 508a and the second layer 508b allow light having a wavelength of 500 nm to 750 nm to pass through. The second layer 508b is bonded to the entire front surface 514 of the first layer 508a.

[0056] According to another embodiment, in FIG. 7, the method for manufacturing the contact lens 600 includes the following steps. The first step 601 includes obtaining one or more colorants that absorb light having a wavelength from 450 nm to 495 nm and allow light having a wavelength from 500 nm to 750 nm to pass through. Another step 603 includes forming a diffractive optical element (DOE) having a diffractive structure capable of focusing visible light having a wavelength greater than 495 nm. Another step 611 includes forming a contact lens incorporating the diffractive optical element and one or more colorants. FIG. 7 shows optional steps in dashed boxes and essential steps in solid boxes.

[0057] According to another embodiment, the step 611 of forming the contact lens further includes the following steps. Step 605 includes molding a lens body around the diffractive optical element such that the diffractive optical element is embedded in the lens body. Step 607 includes forming a layer incorporating one or more colorants. Step 609 includes bonding the rear surface of the layer to the front surface of the lens body. According to another embodiment, prior to the step 611 of forming the contact lens, the method includes a step 604 of obtaining one or more compounds that absorb UV light.

[0058] According to another embodiment, in FIG. 8, the method 700 for correcting a user's vision includes the following steps. The first step 702 includes obtaining a contact lens according to the present disclosure. The second step 704 includes placing the contact lens on the surface of the user's eye. The third step 706 includes diffracting the incident light on the contact lens such that the light is focused on the retina of the user's eye.

[0059] Although the present disclosure has been described and illustrated with reference to specific embodiments, those skilled in the art will understand that the present disclosure is applicable to many different variations not specifically illustrated herein. As an example, possible variations are described below.

[0060] In some alternative embodiments of the present disclosure, the contact lens can include a coating. The coating can be directly applied to the contact lens surface by various coating methods such as spray coating, spin coating, solvent casting, liquid phase surface deposition, vapor phase surface deposition, etc. Before applying the coating to the contact lens surface, the contact lens surface can be treated using, for example, plasma treatment, etc., to improve the bonding or adhesion with the coating layer. The coating can include one or more colorants configured to filter light having a wavelength from 450 nm to 495 nm. The coating can be configured to allow light having a wavelength from 500 nm to 750 nm to pass through. The coating can be an optical filter. The coating can include one or more compounds configured to absorb UV light.

[0061] In the above description, when a complete body or element having known obvious or predictable equivalents is mentioned, such equivalents are incorporated herein as if individually shown. Please refer to the claims to determine the true scope of the present disclosure, which should be construed as encompassing all equivalents. The reader will also understand that the complete bodies or features of the present invention described as preferred, beneficial, convenient, or the like are optional and do not limit the scope of the independent claims. Furthermore, although such optional complete bodies or features may bring benefits in some embodiments of the present invention, they may not be desirable in other embodiments and thus may not exist in other embodiments.

Explanation of Reference Numerals

[0062] 100 Contact lens 101 Diffractive optical element 103 Optical filter 104 First part 106 Second part 107 Peripheral part 109 Optical axis

Claims

1. A contact lens including a diffractive optical element, an optical filter, and an optical axis passing through the optical filter and the diffractive optical element, wherein the diffractive optical element is configured to focus visible light, and the optical filter is configured to filter light having a wavelength from 450 nm to 495 nm. The contact lens.

2. The contact lens according to claim 1, wherein the optical filter allows light having a wavelength from 500 nm to 750 nm to pass through.

3. The contact lens according to claim 1 or 2, wherein the optical filter includes one or more colorants.

4. The contact lens according to any one of claims 1 to 3, wherein the contact lens includes a material having one or more colorants dispersed therein.

5. The contact lens according to any one of claims 1 to 3, wherein the contact lens includes a layer including the optical filter.

6. The contact lens according to claim 5, wherein the layer forms a front surface of the contact lens.

7. The contact lens according to any one of claims 1 to 6, wherein the diffractive optical element is embedded in the contact lens.

8. The contact lens according to any one of claims 1 to 7, wherein the diffractive optical element is centered on the optical axis of the contact lens and surrounded by a peripheral region of the contact lens.

9. The contact lens according to any one of claims 1 to 8, wherein the specific wavelength of the diffractive optical element is from 500 nm to 750 nm.

10. The contact lens according to any one of claims 1 to 9, wherein the optical filter absorbs UV wavelengths.

11. The contact lens according to any one of claims 1 to 10, wherein the diffractive optical element includes a diffraction structure that diffracts and refracts incident light.

12. In a cross section passing through the optical axis, the diffractive optical element includes a series of ridges and valleys having a first refractive index, and the valleys are filled with a material having a second refractive index. The contact lens according to any one of claims 1 to 11.

13. The diffractive optical element includes a first portion having a first refractive index and a second portion including a liquid crystal cell that can be switched between a aligned state and a non-aligned state. In the integrated state, the refractive index of the liquid crystal cell is the same as the first refractive index, In the non-integrated state, the refractive index of the liquid crystal cell is different from the first refractive index. The contact lens according to any one of claims 1 to 11.

14. A method for manufacturing a contact lens, comprising: obtaining one or more colorants that absorb light having a wavelength of 450 nm to 495 nm and allow light having a wavelength of 500 nm to 750 nm to pass through; forming a diffractive optical element having a diffractive structure configured to focus visible light having a wavelength higher than 495 nm; forming a contact lens incorporating the diffractive optical element and the one or more colorants; A manufacturing method including.

15. The step of forming the contact lens includes molding a lens body around the diffractive optical element such that the diffractive optical element is embedded in the lens body, forming a layer incorporating one or more colorants; joining the rear surface of the layer to the front surface of the lens body; The manufacturing method according to claim 14, including.

16. The method further includes obtaining one or more compounds that absorb UV light before forming the contact lens, and the step of forming the contact lens includes incorporating the one or more compounds into the contact lens. The manufacturing method according to claim 14.

17. A method for correcting a user's vision, comprising: obtaining a contact lens according to any one of claims 1 to 13; placing the contact lens on the surface of the user's eye; including, The contact lens diffracts the light so that the light is focused on the retina of the user's eye.

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