Double-sided aspheric diffractive multifocal lenses, their manufacture and use

Abstract

A double-sided aspheric diffractive multifocal lens for ophthalmology and methods for manufacturing and designing such a lens are described. The lens includes an optic with an aspheric anterior surface and an aspheric posterior surface. Multiple concentric diffractive multifocal zones are designed on one of the two surfaces. The other surface may include a toric component. The double-sided aspheric surface design results in an improved modulation transfer function (MTF) of the lens-eye combination and enhanced visual contrast due to reduced aberrations compared to single-sided aspheric lenses. The surface with multiple concentric diffractive multifocal zones provides near, intermediate, and far focus. The phase step of the diffractive annular lens zone is shaped like a sinusoidal profile. TIFF2023529241000024.tif51158

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority under 35 USC §119(e) to U.S. patent application Ser. No. 63 / 032,892, filed June 1, 2020, the entire contents of which are incorporated by reference in their entirety.

[0002] Field The present disclosure relates generally to ophthalmic lenses, and more particularly to novel bi-aspheric diffractive multifocal lenses, their design, manufacture, and use. [Background technology]

[0003] background Ophthalmology is the medical branch that deals with the anatomy, physiology, and diseases of the human eye. The anatomy of the human eye is quite complex. The main structures of the eye include the cornea, a spherical transparent tissue at the front outer part of the eye; the iris, the colored part of the eye; the pupil, a conformable aperture in the iris that regulates the amount of light received in the eye; the lens, a small transparent disk inside the eye that focuses light rays onto the retina; and the retina, a layer that forms the rear or back surface of the eye and converts sensed light into electrical impulses that travel up the optic nerve to the brain. The posterior chamber, the space between the retina and the lens, is filled with aqueous humor, and the anterior chamber, the space between the lens and the cornea, is filled with vitreous humor, a clear, jelly-like substance.

[0004] The natural crystalline lens is a flexible, transparent, biconvex structure that works with the cornea to refract light and focus it on the retina. The crystalline lens is flatter at its front than at its back, and its curvature is controlled by the ciliary muscle; it is connected to the ciliary muscle by a suspensory ligament called the zonules. By changing the curvature of the crystalline lens, the focal length of the eye can be changed to focus on objects at different distances. To see objects at a short distance from the eye, the ciliary muscle contracts, causing the crystalline lens to thicken and, as a result, to assume a rounder shape and therefore a higher refractive power. To change the focus to accommodate objects at a greater distance, the crystalline lens must relax and increase its focal length. This process of changing the curvature to accommodate the focal length of the eye to form a sharp image of the object on the retina is called accommodation.

[0005] In humans, the natural refractive power of the crystalline lens is approximately 18-20 diopters, which is roughly one-third of the eye's total optical power. The remaining 40 diopters of the eye's total optical power are provided by the cornea.

[0006] As the eye ages, the lens becomes less opaque, which is called a cataract. Some diseases like diabetes, trauma, some medications, and overexposure to UV light can also cause cataracts. Cataracts are painless and result in cloudy, blurred vision. Treatment of cataracts involves surgery to remove the cloudy lens and replace it with an artificial lens, commonly called an intraocular lens (IOL or IOLs).

[0007] Another age-related effect is called presbyopia, which manifests as difficulty reading small print or seeing close images clearly. Presbyopia is generally believed to be caused by the natural lens inside the eye becoming thicker and less flexible. Age-related changes also occur in the ciliary muscle that surrounds the lens. When the ciliary muscle becomes less elastic, it becomes more difficult for the eye to focus on objects that are close to it.

[0008] Various intraocular lenses are also used to correct other visual disorders, such as myopia, or nearsightedness, the inability to see distant objects, caused by a cornea that is too curvature. The effect of myopia is that light rays coming from far away are focused at a point in front of the retina, rather than on its surface. In hyperopia, or farsightedness, caused by an abnormally flat cornea, light rays entering the eye are focused behind the retina and cannot be focused on nearby objects; and in astigmatism, another common cause of visual difficulties, images are blurred due to an irregularly shaped cornea.

[0009] In the majority of cases, an intraocular lens is implanted in the patient's eye during cataract surgery to replace the natural crystalline lens and compensate for the loss of optical power of the removed crystalline lens. The optics of modern IOLs are designed to have multifocal optics to provide vision for short, intermediate, and long distance objects, also called multifocal IOLs, or more specifically trifocal lenses. Presbyopia can be corrected by glasses or contact lenses, and patients can also opt for multifocal optics. In some cases, IOLs may contain diffractive structures to have not only far-focus power but also near-focus power, thereby providing some degree of pseudoaccommodation. However, various aberrations, such as spherical aberration and astigmatism, can adversely affect the optical performance of such lenses. For example, spherical aberration can impair visual contrast, especially when the pupil size is large.

[0010] Therefore, what is needed is an intraocular lens that can simultaneously provide near, intermediate and far focus and address adverse effects such as spherical aberration and astigmatism, thereby providing enhanced contrast and improved visual acuity. Summary of the Invention

[0011] overview The present disclosure relates to a double-sided aspheric diffractive multifocal lens that can eliminate spherical aberration and astigmatism and provide contrast enhancement and improved vision. In some embodiments, the diffractive multifocal lens may include a lens body, which may include a first aspheric surface and a second aspheric surface including a central zone and a plurality of diffractive elements; the plurality of diffractive elements includes radially extending concentric annular zones, each of which has a periodic structure curve with two smooth turning points between two sharp turning points, thereby providing a near focus (f2), an intermediate focus (f1), and a far focus (f0).

[0012] In some embodiments, the first aspheric surface is the anterior surface and the second aspheric surface is the posterior surface. In some embodiments, the first aspheric surface may include a toric component. In some embodiments, the height profile of the first aspheric surface and / or the second aspheric surface is represented by the formula: TIFF0007620700000001.tif13128, where Z asp is the height profile of the aspheric structure, r is the radial distance in millimeters, c is the curvature, k is the conic constant, A i are the high-order aspheric coefficients.

[0013] In some embodiments, the height profile of the diffractive elements is represented by the formula: TIFF0007620700000002.tif7128Here, λ is the design wavelength, Φ (n) (r) is the phase profile, n1 is the refractive index of the lens material, and n0 is the refractive index of the medium covering the lens.

[0014] In some embodiments, the phase profile Φ (n) (r) can be expressed as: TIFF0007620700000003.tif12128 where r is the radial distance of the lens in millimeters, r n is the radius of the nth zone, r n+1is the radius of the (n+1)th zone, and A, B, C, and D are the light distribution parameters. A is the amplitude, B is where C is the phase shift, D is the vertical shift, and D is the period as TIFF0007620700000004.tif6128.

[0015] In some embodiments, the phase profile Φ (n) (r) is -4π ≦ Φ (n) (r) may be in the range of ≦4π. In some embodiments, the far focus (f0), the mid focus (f1), and the near focus (f2) are in the range of: TIFF0007620700000005.tif7128.

[0016] In some embodiments, the diffractive multifocal lens may be an intraocular lens (IOL). In some embodiments, the diffractive multifocal lens may further include a pair of haptics extending outward from the lens body. In some embodiments, the IOL is a posterior chamber IOL, and the posterior chamber IOL is configured to be implanted in the capsular bag of a human eye.

[0017] In some embodiments, the present disclosure relates to a method of treating an ophthalmic disease or disorder in a subject; the method may include implanting a diffractive multifocal lens comprising a lens body into an eye of the subject; the lens body may include a first aspheric surface and a second aspheric surface comprising a central zone and a plurality of diffractive elements; the plurality of diffractive elements comprises radially extending concentric annular zones, each of which has a periodic structure curve with two smooth turning points between two sharp turning points.

[0018] In some embodiments, the present disclosure relates to a method for producing a diffractive multifocal lens; the method may include: (a) producing a first aspheric surface, optionally comprising a toric component; (b) producing a second aspheric surface; and (c) generating a diffractive element on the second aspheric surface, comprising a central zone and a plurality of concentric annular zones, each of which has a periodic structure of curves with two smooth turning points between two sharp turning points, thereby providing a near focus (f2), an intermediate focus (f1), and a far focus (f0). In some embodiments, the method may further include performing an in situ image quality analysis to ensure performance meets pre-established quality standards. [The present invention 1001] (a) a first aspheric surface; (b) a second aspheric surface having a central zone and a plurality of diffractive elements, the plurality of diffractive elements comprising radially extending concentric annular zones, each of the concentric annular zones having a periodic structure curve with two smooth turning points between two sharp turning points, thereby achieving a near focus (f 2 ) and intermediate focus (f 1 ) and far focus (f 0 ) and a second aspheric surface providing A lens body having A diffractive multifocal lens comprising: [The present invention 1002] The diffractive multifocal lens of the present invention 1001, wherein the first aspheric surface is the front surface. [The present invention 1003] The diffractive multifocal lens of the present invention 1001, wherein the second aspheric surface is the posterior surface. [The present invention 1004] 1001. A diffractive multifocal lens according to the present invention, wherein the first aspheric surface has a toric component. [The present invention 1005] the height profile of the first aspheric surface and / or the second aspheric surface is TIFF0007620700000006.tif13128 In the above formula, Z asp is the height profile of the aspheric structure, r is the radial distance in millimeters, c is the curvature, k is the conic constant, A i is a high-order aspheric coefficient, the diffractive multifocal lens of the present invention 1001. [The present invention 1006] The height profile of the diffractive element is TIFF0007620700000007.tif7128 In the above formula, λ is the design wavelength, Φ (n) (r) is the phase profile, n 1 is the refractive index of the lens material, n 0 is the refractive index of the medium covering the lens, 1001 being a diffractive multifocal lens of the present invention. [The present invention 1007] Phase profile Φ (n) (r) TIFF0007620700000008.tif12128 where r is the radial distance of the lens in millimeters, r n is the radius of the nth zone, r n+1 is the radius of the (n+1)th zone, A, B, C, and D are the light distribution parameters, where A is the amplitude; B is TIFF0007620700000009.tif7128 A is the period; B is the phase shift; and D is the vertical shift. [The present invention 1008] Phase profile Φ (n) (r) TIFF0007620700000010.tif5128 The diffractive multifocal lens of the present invention 1006 is within the range. [The present invention 1009] Far focus (f 0 ), intermediate focus (f 1 ), and near focus (f 2 )but TIFF0007620700000011.tif7128 The diffractive multifocal lens of the present invention 1001 is within the range. [The present invention 1010] The diffractive multifocal lens of the present invention 1001, which is an intraocular lens (IOL). [The present invention 1011] The diffractive multifocal lens of the present invention 1010 further comprising a pair of haptics extending outwardly from the lens body. [The present invention 1012] The diffractive multifocal lens of the present invention 1010, wherein the IOL is a posterior chamber IOL. [The present invention 1013] The diffractive multifocal lens of the present invention 1012, wherein the posterior chamber IOL is configured to be implanted within the capsular bag of a human eye. [The present invention 1014] 1. A method of treating an ophthalmic disease or disorder in a subject, comprising: implanting in the subject's eye a diffractive multifocal lens having a lens body; The lens body, (a) a first aspheric surface; (b) a second aspheric surface having a central zone and a plurality of diffractive elements, the plurality of diffractive elements comprising radially extending concentric annular zones, each of the concentric annular zones having a periodic structure of curves with two smooth turning points between two sharp turning points; and Equipped with method. [The present invention 1015] The method of claim 10, wherein the ophthalmic disease or disorder is selected from the group consisting of cataracts and presbyopia. [The present invention 1016] The method of the present invention 1014, wherein the diffractive multifocal lens is an intraocular lens (IOL). [The present invention 1017] The method of claim 1016, wherein the diffractive multifocal lens further comprises a pair of haptics extending outwardly from the lens body. [The present invention 1018] The method of the present invention 1016, wherein the IOL is implanted within the capsular bag of the subject's eye. [The present invention 1019] 1. A method for producing a diffractive multifocal lens, comprising the steps of: (a) producing a first aspheric surface, optionally having a toric component; (b) producing a second aspheric surface; and (c) creating a diffractive element on the second aspheric surface, the diffractive element comprising a central zone and a plurality of concentric annular zones, each of the concentric annular zones having a periodic structure of curves with two smooth turning points between two sharp turning points, thereby achieving a near focus (f 2 ) and intermediate focus (f 1 ) and far focus (f 0 ) and bring about a stage A method comprising: [The present invention 1020] performing an in situ image quality analysis to ensure performance meets pre-established quality standards; The method of the present invention 1019 further comprises: [Brief description of the drawings]

[0019] [Figure 1A] 1 shows a top view of a double-sided aspheric multifocal diffractive IOL according to some embodiments of the present disclosure. [Figure 1B] 1 illustrates a cross-sectional view of a double-sided aspheric multifocal diffractive IOL according to some aspects of the present disclosure. [Figure 2A] 1 illustrates a blown up view of a lens body of an IOL according to some embodiments of the present disclosure. [Figure 2B] 1 illustrates a height profile of a diffractive element according to some aspects of the present disclosure. [Figure 2C] 1 illustrates a height profile of a diffractive element according to another aspect of the present disclosure. [Figure 3A] 1 illustrates optical performance (modulation transfer function, MTF) at 3 mm aperture and 50 LP / mm resolution measurements with parameter variations according to a first embodiment of the present disclosure. [Figure 3B] 1 illustrates a height profile of a combination aspheric and diffractive structure according to a first aspect of the present disclosure. [Figure 4A]1 illustrates optical performance (MTF) at 3 mm aperture and 50 LP / mm resolution measurements with parameter variations according to a second embodiment of the present disclosure. [Figure 4B] 1 illustrates the height profile of a combination aspheric and diffractive structure according to a second aspect of the present disclosure. [Figure 5A] 13 illustrates optical performance (MTF) at 3 mm aperture and 50 LP / mm resolution measurements with parameter variations according to a third embodiment of the present disclosure. [Figure 5B] 13 illustrates the height profile of a combination aspheric and diffractive structure according to a third aspect of the present disclosure. [Figure 6] 1 is a flow chart illustrating the design and manufacture of a double-aspheric multifocal diffractive IOL according to some aspects of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Detailed Description The present disclosure relates to a bilateral aspheric diffractive multifocal lens in the field of ophthalmology and a method for designing and manufacturing such a lens. The lens may include an aspheric anterior surface and an aspheric posterior surface. One of the two surfaces may include multiple concentric diffractive multifocal zones. The other surface optionally includes a toric component. The bilateral aspheric surface design results in improved modulation transfer function (MTF) of the lens-eye combination due to reduced aberrations and enhanced visual contrast compared to a single-sided aspheric lens. A surface with multiple concentric diffractive multifocal zones may provide near, intermediate and far focus.

[0021] Multifocal IOLs are widely used to treat presbyopia, a condition in which the eye exhibits a progressive decrease in the ability to focus on nearby objects. Humans begin to develop presbyopia as they age, and the effects typically become noticeable around age 40-45, when they notice the need for reading glasses. Presbyopic people who wear corrective lenses may find that they need two separate prescriptions, preferably within the same bifocal lens, one for reading (near) and one for driving (distance). Trifocal lenses may further improve vision at intermediate distances, for example when working at a computer.

[0022] Diffractive IOLs may have repeating structures that may be formed on the surface of the optical element by fabrication methods such as cutting the surface with a lathe, which may have a cutting head made of a hard material such as diamond or sapphire; direct write patterning with a high energy beam such as a laser beam or an electron beam, or similar methods of ablating the surface; etching the surface with a photolithographic patterning process; or molding the surface. The diffractive structure is typically a series of concentric annular zones, which requires that each zone is progressively narrower from the center to the edge of the lens. There may be, for example, about 5 to 30 zones between the center and edge of the lens. The surface profile within each zone is typically a smoothly varying function, such as an arc, a parabola, or a straight line. At the periphery of each zone, there is a discontinuous step in the vertical surface profile. The resulting surface structure can act as a circularly symmetric diffraction grating that disperses light into multiple diffractive dimensions, each diffractive dimension having a consecutive number, such as 0, 1, 2, 3, etc.

[0023] Diffractive IOL lenses may be used to correct presbyopia. In such applications, the lens may include one refractive surface and one diffractive surface. Indeed, the light energy passing through a diffractive lens is typically concentrated into one, two, or three diffractive dimensions, while the light energy contributed to the other diffractive dimensions is insignificant.

[0024] Existing designs for multifocal IOLs use either refractive optics, combined refractive / diffractive designs, or diffractive lenses that direct light into a single diffractive dimension. However, fabrication of such IOLs can be time consuming and expensive. Thus, there is a need for improved ophthalmic lenses, and in particular improved diffractive IOLs that are more easily fabricated.

[0025] The present disclosure relates to an intraocular lens (IOL) that provides an extended visual range. FIG. 1A shows a top view of a bilaterally aspheric multifocal diffractive IOL 100 according to some embodiments of the present disclosure. FIG. 1B shows a cross-sectional view of a bilaterally aspheric multifocal diffractive IOL 100 according to some embodiments of the present disclosure. The IOL 100 may include an optically transparent circular disk-shaped lens body 101 with an optic diameter 106 and a central thickness 110, and a pair of haptics 102 as flexible supports that support the IOL when implanted in a patient's eye, with an overall outer diameter 107. The lens body 101 may include an anterior surface 108, a posterior surface 109, a central zone 103, and a plurality of diffractive elements 104 on the posterior surface 109. The lens body 101 may include an optical axis 105 extending across the anterior surface 108 and the posterior surface 109. Those skilled in the art will recognize that optical axis 105 is an imaginary axis for purposes of referring to the optical properties of IOL 100. A pair of haptics 102 may extend outwardly from lens body 101 to support IOL 100 after implantation in a human eye. In some embodiments, haptics 102 of IOL 100 can hold the IOL in place within the capsular bag.

[0026] In some embodiments, the lens body 101 may take on a biconvex shape. Other shapes for the lens body 101 may include, without limitation, plano-convex, biconcave, plano-concave, or a combination of convex and concave shapes. In some embodiments, both the anterior surface 108 and the posterior surface 109 may feature aspheric structures, which may provide bilateral asphericity for the IOL 100.

[0027] The diffractive elements 104 may include diffractive rings or steps, also known as diffractive zones, with characteristic radial separation to provide constructive interference at a characteristic focal point on the optical area of ​​the IOL. In some embodiments, the diffractive elements 104 may include from about 3 to about 30 diffractive rings / zones. In some embodiments, the diffractive elements 104 may include about 5, 10, 15, 20, or 25 diffractive rings / zones. The IOL may contain diffractive elements on one or both of the surfaces of the lens. In some embodiments, the diffractive elements 104 may be placed on the posterior surface of the IOL. In some embodiments, the diffractive elements may be placed on the posterior surface because there is less light scattering effect on the posterior surface than on the anterior surface. The plurality of diffractive elements 104 may include rings or zones extending concentrically about an optical axis 105 through the central zone 103 across at least a portion of the posterior surface 109 of the lens body 101. The diffractive elements 104 may provide a focal point for far, intermediate, and / or near distances. In some embodiments, the diffractive elements 104 are not limited to concentric circular or annular ring shaped zones, but may also include concentric elliptical or oval shaped zones.

[0028] In some embodiments, the optic diameter 106 of the lens body 101 may be about 4 to about 8 mm, and the overall outer diameter 107 of the IOL 100, including the haptics 102, may be about 9 to about 18 mm. The lens body 101 may have a center thickness 110 of about 0.8 to about 1.2 mm. Although the embodiment in Figures 1A and 1B is directed to a posterior chamber IOL, other ophthalmic lenses, including multifocal diffractive contact lenses or spectacle lenses, may also benefit from the same approach. When used with ophthalmic multifocal contact lenses and spectacle or eye glass lenses, the haptics 102 are not provided.

[0029] The amount of correction an ophthalmic lens provides is called optical power and is expressed in diopters (D). Optical power is calculated as the inverse of the focal length f measured in meters; the focal length can be the distance from the lens to the respective focus for distance, intermediate, or near vision. The lens body 101 in the bilateral aspheric shape of the present disclosure may provide a base optical power of about 10 to about 25 D. In some embodiments, the lens body 101 may provide a base optical power of about 12, 14, 16, 18, 20, 22, or 24 D. The plurality of diffractive elements 104 may provide an add power of f1=f0+2.2D and f2=f0+3.3D.

[0030] The IOL may be made of a flexible material, which is advantageous in that it allows temporary deformation to reduce the overall apparent circumference to facilitate insertion through the cornea and concomitantly allows the use of reduced size corneal incisions. In some embodiments, the lens body may comprise polypropylene, polycarbonate, polyethylene, acrylic-butadiene styrene, polyamide, polychlorotrifluoroethylene, polytetrafluoroethylene, polyvinyl chloride, polyvinylidene fluoride, polyvinyl chloride, polydimethylsiloxane, polyethylene terephthalate, ethylene tetrafluoroethylene, ethylene chlorotrifluoroethylene, perfluoroalkoxy, polymethylpentene, polymethylmethacrylate, polystyrene, polyetheretherketone, tetrafluoroethylene, polyurethane, poly(methylmethacrylate), poly(2-hydroxyethylmethacrylate), nylon, polyether block amide, silicone, or mixtures thereof.

[0031] In some embodiments, the lens body may comprise a hydrophilic polymer made of monomers selected from the group consisting of 2-acrylamido-2-methylpropanesulfonic acid, 2-hydroxyethyl methacrylate, N-vinylpyrrolidone, vinylbenzyltrimethylammonium salt, diethylaminoethyl methacrylate, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminomethyl methacrylate, tertiary butylaminoethyl acrylate, tertiary butylaminoethyl methacrylate, and dimethylaminopropyl acrylamide; acrylic acid, methacrylic acid, styrenesulfonic acid, and salts thereof; hydroxypropyl acrylate, vinylpyrrolidone, dimethylacrylamide, ethylene glycol monomethacrylate, ethylene glycol monoacrylate, ethylene glycol dimethacrylate, ethylene glycol diacrylate, triethylene glycol diacrylate, and triethylene glycol methacrylate. In some embodiments, these hydrophilic monomers are surface grafted onto the polymer matrix described in the previous paragraph to create the lens body. In some embodiments, the IOLs of the present disclosure may be made from polymer compositions described in US Pat. No. 10,494,458, which is incorporated herein by reference in its entirety.

[0032] The haptics of IOLs according to the present disclosure may be made from polymeric materials including, but not limited to, polymethacrylate, polypropylene, polyethylene, polystyrene, and polyacrylate.

[0033] The surface of an IOL may contain spherical, aspheric, or toric elements. Spherical surfaces can cause spherical aberration; spherical aberration is a type of optical imperfection that can cause increased glare and reduced overall visual quality, especially in low light or darkness. Aspheric lenses may correct spherical aberration. Aspheric IOLs may provide improved contrast sensitivity, enhanced functional vision, and better night driving capabilities.

[0034] Toric elements are typically used to correct astigmatic eyes. In general, astigmatism is an optical defect in which the eye is unable to focus a point object on the retina as a sharply focused image, resulting in blurred vision. This may result from irregular curvature of the cornea and / or lens. The refractive error of an astigmatic eye results from differences in the degree of curvature, and therefore the degree of refraction, of different meridians of the cornea and / or lens, which causes the eye to have two foci, one for each meridian. As used herein, meridian includes one of two axes relative to a curved surface, such as the prime meridian on the Earth. Meridians may be orthogonal to each other. As an example, meridians on the Earth may be any orthogonal lines of longitude and latitude that curve along the surface of the Earth.

[0035] For example, in an astigmatic eye, an image may be sharply focused on the retina in the horizontal (sagittal) plane, but focused behind the retina in the vertical (tangential) plane. In cases where the astigmatism arises from the cornea alone, the two meridians of astigmatism may be the two axes of the cornea. If the astigmatism arises from the lens, the two meridians of astigmatism may be the two axes of the lens. If the astigmatism arises from a combination of the cornea and lens, the two meridians of astigmatism may be the respective axes of the combined cornea and lens.

[0036] Astigmatism resulting from the cornea or crystalline lens, or a combination of the two, may be corrected by lenses containing a toric component. A toric surface resembles a section of the surface of a football, with two regular radii of curvature, one smaller than the other. These radii may be used to correct the defocus in two meridians of an astigmatic eye. Thus, the blurred vision caused by astigmatism may be corrected by corrective lenses, such as spectacles, hard contact lenses, contact lenses, and / or IOLs, or laser vision correction, that provide adaptive optics specifically rotated around the optical axis.

[0037] In some embodiments, an IOL according to the present disclosure may provide far vision for viewing objects at distances ranging from about infinity to about 4 meters (m). In some embodiments, an IOL of the present disclosure may provide near vision for viewing objects at distances less than about 0.4 m. In some embodiments, an IOL of the present disclosure provides intermediate vision for viewing objects at distances ranging from about 0.4 to about 1 m, about 2 m, about 3 m, or about 4 m. As a result, an IOL of the present disclosure advantageously provides a degree of accommodation for different distance ranges, typically referred to as pseudoaccommodation. In some embodiments, when implanted in a patient's eye, the combined power of the cornea of ​​the eye and the near, intermediate, and distance powers of the IOL of the present disclosure may enable light from objects within the patient's near, intermediate, and far distance ranges to be focused onto the retina. In some embodiments, the far focus (f0), intermediate focus (f1), and near focus (f2) provided by an IOL of the present disclosure may have the following ranges: TIFF0007620700000012.tif26128.

[0038] FIG. 2A shows a blown-up view of a lens body 101 including a front surface 108, a rear surface 109, an optical axis 105, a central zone 103, and a number of diffractive elements 104 generated on the rear surface. The central zone 103 and the diffractive elements 104 are further illustrated in FIG. 2B. The central zone starts from the 0th Fresnel zone (d0 to d1). The diffractive elements are configured as smooth curves (d2 to d3) of periodic structures, and each periodic structure of the diffractive elements contains two smooth turning points (e1, e2) between two sharp turning points (d2, d3). FIG. 2C illustrates another embodiment of the present disclosure by smoothing the two smooth turning points (e1, e2) and their corresponding turning points in a periodic manner.

[0039] The diffractive structures embodied on the IOLs of the present disclosure can be designed using formulas (I)-(IV) as described below.

[0040] Pupil function. The pupil function is a characteristic function of a lens that describes the physical effects of a lens that can change the state of light incident on the lens, specifically, the amplitude function A(r) and the phase function Φ as described in the following equation (I): (n) It is expressed by multiplying it with the exponential function of (r). TIFF0007620700000013.tif5128T(r): Pupil function A(r): Amplitude function Φ (n) (r): Phase function n: natural number

[0041] Phase function. The phase function is defined as a mathematical function that represents the physical effect provided by a lens, such as changing the phase (position of the peaks and valleys of the waves) of the light incident on the lens by any method. The variables of the phase function are mainly expressed by the position r in the radial direction from the center of the lens, and the phase of the light incident on the lens at the point of position r is expressed by the phase function Φ (n) The phase is emitted from the lens with a change due to (r). Specifically, this is represented by the r-Φ coordinate system. In this disclosure, the phase is described as Φ, and the unit is radians. For example, one wavelength of light is represented as 2π radians, and a half wavelength is represented as π radians. The distribution of phase in the entire area to which the phase function is provided, represented in the same coordinate system, is called a phase profile, or simply a profile, or a zone profile. If the r-axis of Φ=0 is taken as a reference line, this means that the light incident at the point of Φ=0 is emitted without a change in phase. Also, for this reference line, when a positive value of Φ is used, this means that the light travels slower by that phase amount, and when a negative value of Φ is used, this means that the light travels faster by that phase amount. In an actual ophthalmic lens, a refractive surface to which no diffractive structure is applied corresponds to this reference line (surface). The light is emitted from the lens with a phase change based on this phase function.

[0042] Amplitude function. The amplitude function is the function represented by A(r) in formula (I) above. In this disclosure, it is defined as a function that represents the change in the amount of light transmission when passing through a lens. The variable of the amplitude function is represented as the position r in the radial direction from the center of the lens, and represents the transmittance of the lens at the point of position r. And, the amplitude function is in the range from 0 to 1, which means that at the point A(r)=0, no light is transmitted, and at the point A(r)=1, the incident light is transmitted as it is without loss.

[0043] Zone: In this disclosure, a zone is used as the smallest unit within a diffractive structure, element, or grating provided in a lens.

[0044] The height profile (Z diff ) can be calculated based on the following formula (II): TIFF0007620700000014.tif7128Z diff (r): Height profile of the diffractive structure Φ (n) (r): Phase function λ: Design wavelength n1: Refractive index of the lens material n0: Refractive index of the medium covering the lens

[0045] The radius of a particular diffraction zone (r n ) can be calculated based on the following formula (III): TIFF0007620700000015.tif5128r n : radius of the nth zone λ: Design wavelength f: Reciprocal of additional frequency

[0046] Phase function (Φ (n) (r)) can be calculated by the following formula (IV). TIFF0007620700000016.tif10128Φ (n) (r): Phase function r: radial distance from the center of the lens r n: radius of the nth zone r n+1 : radius of the (n+1)th zone where A, B, C, and D are light distribution parameters. A is the amplitude; B is TIFF0007620700000017.tif6128 is the period;C is the phase shift, a +C shifts to the left and a -C phase shift shifts to the right;D is the vertical shift, +D moves the function up and -D moves the function down.

[0047] The double aspheric structure (on the anterior and posterior surfaces of the optic area of ​​the IOL) is intended to correct the spherical aberration of the lens. asp ) can be calculated based on the following formula (V): TIFF0007620700000018.tif8128Z asp : Height profile of aspheric structure r: radial distance from the center of the lens k: conic constant c: curvature A i : High-order aspheric coefficients

[0048] According to some aspects of the present disclosure, when both aspheric and diffractive structures are placed on the same surface (the anterior and / or posterior surfaces of an IOL), the height profile (Z total ) is the height profile (Z asp ) and the height profile (Z diff ) and TIFF0007620700000019.tif5128Z diff : Height profile of the diffractive structure Z aspheric : Height profile of aspheric structure Z total : Combination structure, i.e., height profile of the lens body

[0049] In some embodiments, the lens may be a contact lens or an IOL. In some embodiments, the IOL may be an intracorneal IOL, an anterior chamber IOL, or a posterior chamber IOL. In some embodiments, the IOL may be a posterior chamber IOL. Although haptic arms are illustrated in the embodiments of the present disclosure, any suitable haptic fixation structure to the capsular bag or ciliary sulcus that is compatible with posterior chamber implantation may also be used in posterior chamber IOLs.

[0050] One way to estimate the optical priority of an intraocular lens is to experimentally determine its modulation transfer function (MTF). The MTF of an optical system can be measured according to Annex C of ISO 11979-2 and reflects the ratio of contrast transmitted through the optical system for a determined spatial frequency of a test pattern; spatial frequency is defined as "cycles / mm" or "LP / mm", where "LP" stands for "line pair". In general, contrast decreases with increasing spatial frequency.

[0051] All publications, patents, and patent applications mentioned in this disclosure are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this disclosure belongs. Any method and material similar or equivalent to those described herein may be used in practicing or testing this disclosure, but it will be understood that modifications and variations are included within the spirit and scope of this disclosure. Preferred methods and materials are described below.

[0053] Presented below are examples that describe different aspects of the IOLs anticipated for the applications described in this disclosure. The following examples are provided to further illustrate aspects of the present disclosure, but are not intended to limit the scope of the present disclosure. They are representative of those that may be used, but other procedures, methodologies, or techniques known to those skilled in the art may alternatively be used. EXAMPLES

[0054] Example 1 MTF and height profile of an IOL according to the first aspect of the present disclosure From equation (IV), the optical performance (modulation transfer function, MTF) at 3 mm aperture and 50 line pairs per millimeter (LP / mm) resolution measurements by varying parameters A, B, C, and D and controlling the far focus (f0), mid focus (f1), and near focus (f2) are shown in Figure 3A. The parameters A, B, C, and D were varied according to Table 1 below.

[0055] Table 1: Variations in parameters A to D in the first embodiment of the present disclosure TIFF0007620700000020.tif74128

[0056] The curve in FIG. 3A shows three peaks corresponding to a far focus at about 14.0 D, a mid focus at about 16.2 D, and a near focus at about 17.3 D, respectively.

[0057] Height profile Z of combined aspheric and diffractive structure total (r) is shown in Figure 3B. Height is plotted in μm scale along the vertical axis. The optical axis passing through the center of the lens body is assumed to be at radial position r = 0, and the radial distance r measured outward from the optical axis is expressed in mm along the vertical axis.

[0058] Example 2 MTF and height profile of an IOL according to the second aspect of the present disclosure From equation (IV), the optical performance (MTF) at 3 mm aperture and 50 line pairs per millimeter (LP / mm) resolution measurements by varying parameters A, B, C, and D and controlling f0, f1, and f2 is shown in FIG. 4A. The parameters A, B, C, and D were varied according to Table 2 below. The height profile Z of the combined aspheric and diffractive structure is total (r) is shown in Figure 4B.

[0059] Table 2: Variations of parameters A to D in the second aspect of the present disclosure TIFF0007620700000021.tif74128

[0060] The curve in FIG. 4A shows three peaks corresponding to a far focus at about 24.0 D, a mid focus at about 26.2 D, and a near focus at about 27.3 D, respectively.

[0061] Example 3 MTF and height profile of an IOL according to the third aspect of the present disclosure From equation (IV), the optical performance (MTF) at 3 mm aperture and 50 line pairs per millimeter (LP / mm) resolution measurements by varying parameters A, B, C, and D and controlling f0, f1, and f2 is shown in FIG. 5A. The parameters A, B, C, and D were varied according to Table 3 below. The height profile Z of the combined aspheric and diffractive structure is total (r) is shown in Figure 5B.

[0062] Table 3: Variations in parameters A to D in the third aspect of the present disclosure TIFF0007620700000022.tif75128

[0063] The curve in FIG. 5A shows three peaks corresponding to a far focus at about 19.0 D, a mid focus at about 21.2 D, and a near focus at about 22.3 D, respectively.

[0064] 6 is a flow chart 600 illustrating the design and manufacture of a bi-aspheric multifocal diffractive IOL according to some embodiments of the present disclosure. In step 601, a first aspheric surface, optionally including a toric component, is manufactured. In step 602, a second aspheric surface is manufactured. In step 603, a plurality of concentric diffractive multifocal zones are created on the second aspheric surface to provide near, intermediate, and far focus. In step 604, an in situ image quality analysis of the bi-aspheric diffractive multifocal lens is performed on the ISO Model Eye 2 to measure the through-focus MTF using the TRIOPTICS OptiSpheric® IOL PRO 2 against pre-established performance criteria.

[0065] While the present invention has been particularly shown and described with reference to specific embodiments, it will be understood by those skilled in the art that various changes in form and detail of the invention can be made without departing from the spirit and scope of the disclosure disclosed herein.

[0066] All references referred to in this disclosure are incorporated herein by reference in their entirety. Various aspects of the disclosure may be characterized by potential claims, which are recited in the paragraphs following this paragraph (and preceding the actual claims provided at the end of this application). These potential claims form part of the written description of this application. Thus, the content of the following potential claims may be presented as actual claims in a later proceeding of this application or any application claiming priority from this application. The inclusion of such potential claims should not be construed to mean that the actual claims do not cover the content of the potential claims. Thus, a decision not to present these potential claims in a later proceeding should not be construed as a donation of their content to the public.

[0067] The embodiments of the disclosure described above are intended to be illustrative only; numerous variations and modifications will be apparent to those skilled in the art. All such variations and modifications are intended to be within the scope of the disclosure, as defined in the appended claims.

Claims

1. (a) a first aspheric surface; (b) a second aspheric surface having a central zone and a plurality of diffractive elements, the plurality of diffractive elements comprising radially extending concentric annular zones, each of which has a curve of a periodic structure having two smooth turning points between two sharp turning points, the slope of the curve of the periodic structure changing sign at each of the two smooth turning points in each of the concentric annular zones, thereby improving near focus (f 2 ) and intermediate focus (f 1 ) and far focus (f 0 ) and a second aspheric surface providing A lens body having 1. A diffractive trifocal lens comprising:

2. 2. The diffractive trifocal lens of claim 1, wherein the first aspheric surface is the front surface.

3. 2. The diffractive trifocal lens of claim 1, wherein the second aspheric surface is the posterior surface.

4. 10. The diffractive trifocal lens of claim 1, wherein the first aspheric surface comprises a toric component.

5. the height profile of the first aspheric surface and / or the second aspheric surface is In the above formula, Z asp is the height profile of the aspheric structure, r is the radial distance in millimeters, c is the curvature, k is the conic constant, A i 2. The diffractive trifocal lens of claim 1, wherein:

6. The height profile of the diffractive element is In the above formula, λ is the design wavelength, Φ (n) (r) is Phase profile in the range of n 1 is the refractive index of the lens material, n 0 2. The diffractive trifocal lens of claim 1, wherein is the refractive index of the medium covering the lens.

7. Phase profile Φ (n) (r) where r is the radial distance of the lens in millimeters, r n is the radius of the nth zone, r n+1 is the radius of the (n+1)th zone, A, B, C, and D are the light distribution parameters, where A is the amplitude; B is 7. The diffractive trifocal lens of claim 6, wherein: C is the period as; C is the phase shift; and D is the vertical shift.

8. The diffractive trifocal lens of claim 1, which is an intraocular lens (IOL) sized for insertion into a human eye.

9. 9. The diffractive trifocal lens of claim 8, further comprising a pair of haptics extending outwardly from the lens body.

10. The diffractive trifocal lens of claim 8, which is an IOL sized for insertion into the posterior chamber of the human eye.

11. 11. The diffractive trifocal lens of claim 10, wherein the posterior chamber IOL is configured to be implanted within a capsular bag of a human eye.

12. 1. A method for producing a diffractive trifocal lens comprising the steps of: (a) producing a first aspheric surface, optionally having a toric component; (b) producing a second aspheric surface; and (c) creating a diffractive element on the second aspheric surface, the diffractive element comprising a central zone and a plurality of concentric annular zones, each of the concentric annular zones having a curve of a periodic structure with two smooth turning points between two sharp turning points, the slope of the curve of the periodic structure changing sign at each of the two smooth turning points in each of the concentric annular zones, thereby achieving a near focus (f 2 ) and intermediate focus (f 1 ) and far focus (f 0 ) and bring about a stage A method comprising:

13. performing an in situ image quality analysis to measure a modulation transfer function (MTF) of the trifocal lens using pre-established quality criteria; 13. The method of claim 12, further comprising:

14. A diffractive trifocal lens having a modulation transfer function (MTF) that includes a first peak at an intermediate focus (f1) and a second peak at a near focus (f2), and 2. A diffractive trifocal lens as described in claim 1, wherein the minimum MTF value between the first peak and the second peak is approximately 50% of the maximum MTF value at the first peak, thereby improving visual contrast between the intermediate focus (f1) and the near focus (f2).

15. The optical power of the far focus (f 0 ) is equal to or greater than 0 diopters and equal to or less than 55 diopters; an optical power of the intermediate focus (f1) is greater than the optical power of the far focus (f0) by a first difference in optical power, the first difference being greater than or equal to 1 diopter and less than or equal to 2.5 diopters; the optical power of the near focus (f2) is greater than the optical power of the far focus (f0) by a second difference in optical power, the second difference being greater than or equal to 2 diopters and less than 5 diopters; 2. The diffractive trifocal lens of claim 1.

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