A lens that extends the depth of focus by promoting excessive longitudinal chromatic aberration

Abstract

Disclosed is an implantable lens that includes, among other things, a refractive element that causes chromatic aberration and an element that promotes an increase in chromatic aberration. Further disclosed is a method for manufacturing the implantable lens.

Description

Technical Field

[0001] The following disclosure relates to the field of implantable lenses, such as intraocular lenses (IOLs) or phakic lenses, and more particularly to implantable lenses that promote excessive longitudinal chromatic aberration (LCA), for example, to extend the depth of focus (DoF) of the eye after lens removal.

Background Art

[0002] Treatment of eye diseases may involve removal of the natural lens, for example, in cataract surgery. In these cases, the lost optical power is typically compensated for by an intraocular lens that can be implanted in the position of the previous natural lens. In other cases of eye disease treatment, the natural lens may be left intact, or for example, a phakic lens may be used to correct high refractive errors. Conventionally, in eye disease treatment, a single-focus intraocular lens that converges light to approximately one focal point may be utilized, thereby determining the point at which the patient can see clearly. However, objects located either in front of or behind the focal plane are blurred, and thus these objects cannot be recognized by the patient. Alternatively, a multifocal lens, such as a bifocal or trifocal lens as described in Patent Document 1, which expands the depth of focus by introducing two or more focal planes, may be used. These lenses, for example, divide the incident light into a primary focal point and a secondary focal point, resulting in a reduction in the quality of vision due to the energy distribution. Also, lenses with a standard zone design may exhibit dependence on the pupil of an individual patient. Since chromatic aberration is generally considered to have an adverse effect on the imaging quality of a lens, both single-focus lenses and multifocal lenses are typically configured to achieve reduction of chromatic aberration.

[0003] Patent Document 2 contemplates creating a hyperchromatic lens by combining a refractive structure having a positive refractive power and a diffractive structure.

[0004] Patent Document 3 discloses an ophthalmic lens having a refractive power and a diffractive power realized by a transmissive / surface relief hologram.

[0005] Patent Document 4 and Patent Document 1 propose an ophthalmic lens that applies a diffraction profile to reduce LCA.

[0006] Accordingly, an object of the present invention is to propose an implantable lens that overcomes the drawbacks of known lenses, and particularly with respect to improving the patient's visual range with minimal side effects, and in particular, to meet the needs of pseudophakic patients after cataract surgery, for example, to propose an implantable lens, such as an intraocular lens, that realizes an extended depth of focus.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Means for Solving the Problems

[0008] According to a first exemplary embodiment, this object is achieved by an implantable lens comprising a refractive element that causes chromatic aberration and an element that promotes an increase in chromatic aberration, wherein the element that promotes an increase in chromatic aberration comprises a diffractive structure that is a negative diffractive structure and a kinoform lens structure, and is solved by the implantable lens. Therefore, the diffractive structure can be a negative or divergent kinoform lens structure, and as such can exhibit or result in a negative focal length and can diverge incident light rays. Therefore, the diffractive structure can increase the LCA as a kinoform structure that acts as a negative lens. The negative or divergent kinoform lens structure can reduce the basic refractive power of the refractive component, particularly between -3D and -8D, for example -3.75D or -7.25D.

[0009] As an example, an implantable lens is disclosed that includes a refractive element that causes chromatic aberration and an element that promotes an increase in chromatic aberration, wherein the element that promotes an increase in chromatic aberration includes a diffractive structure having a negative focal length for diverging incident light rays, and this diffractive structure is a kinoform lens structure. As a further example, an implantable lens is disclosed that includes a refractive element that causes chromatic aberration and a diffractive element that promotes an increase in (the chromatic aberration of the) refractive element, wherein the diffractive element that promotes an increase in chromatic aberration includes a negative diffractive structure, and this diffractive structure is a kinoform lens structure.

[0010] The implantable lens can be, for example, an ophthalmic lens, an intraocular lens (IOL), a pseudophakic lens, or an auxiliary lens. The implantable lens can be understood as an intraocular lens (IOL) for implantation (e.g., into the lens capsule), or an auxiliary groove-fixed lens or a phakic intraocular lens. The implantable lens and / or the refractive element can have dimensions (e.g., diameter) of 5.5 to 7 mm (e.g., 6 mm).

[0011] The phakic intraocular lens can be a phakic intraocular lens, and the phakic intraocular lens can be understood as an intraocular lens that is surgically implanted into the eye to correct myopia (i.e., nearsightedness). The phakic intraocular lens can be used when the natural lens remains in the eye as it is.

[0012] The intraocular lens can be understood to be a lens implanted into the eye as part of, for example, the treatment of cataracts or myopia. Such an IOL can be implanted, for example, during cataract surgery, for example, after the natural lens of an eye having cataracts has been removed. The artificial lens IOL aims to mimic the same light focusing function as the natural lens.

[0013] It can be installed in the anterior chamber to function with the existing natural lens and can be used, for example, in refractive correction surgery to change, for example, the optical power of the eye in the case of the treatment of myopia. An auxiliary lens can be understood to be a lens implanted into the eye, for example, in the sulcus, together with another lens, for example, a standard intracapsular lens. The auxiliary lens can also have a different geometry from the IOL. For example, the refractive element of the IOL can be biconvex. That is, both the rear surface and the front surface are convex. In contrast, the refractive element of the auxiliary lens can have one convex surface and the other concave surface, and for example, the refractive element can have a converging meniscus, or a negative or positive meniscus.

[0014] An implantable lens or IOL according to a first aspect can include or can consist of a small (e.g., plastic) lens with side struts (e.g., made of plastic) for holding the lens in place within the capsular bag of the eye's crystalline lens. The support can have a circular or spiral shape, which can enable accurate centering and fixation within the eye. The IOL can be placed, for example, within the anterior chamber, posterior chamber, or within the capsular bag during, for example, cataract surgery. For example, during surgery, the cataractous lens can be removed from its capsular bag and replaced with an implantable lens according to the first exemplary aspect. The implantable lens according to the first exemplary aspect can include or can consist of (or can be made of) a foldable material (i.e., a material that can be folded), thereby enabling insertion through an incision with a maximum diameter of 4 mm and minimizing any damage that can be caused by the surgery and postoperative scarring. For example, the implantable lens according to the first exemplary aspect can include or can consist of (or can be made of) a plastic such as polymethylmethacrylate (PMMA), a hydrophobic acrylic resin (e.g., phenylethyl methacrylate (PEMA) and phenylethyl acrylate (PEA)), a hydrophilic acrylic resin (e.g., polyhydroxyethyl methacrylate (pHEMA)), and / or silicone (e.g., polydimethylsiloxane (PDMS)), thereby preventing postoperative complications associated with scarring.

[0015] The groove can be a ciliary groove that can be understood to be a small space between the posterior surface of the iris base and the anterior surface of the ciliary body. The groove can be utilized to fix an implantable lens according to the first exemplary aspect, thereby achieving good long-term stability and safety.

[0016] The lens capsule can be understood as a bag-like structure remaining in the eye after extracapsular cataract extraction or phacoemulsification. An intraocular lens can be implanted within this structure to reproduce the original crystalline lens state.

[0017] The refractive element causing chromatic aberration can be an optical element that causes refraction and exhibits longitudinal chromatic aberration (LCA). Chromatic aberration may be caused by dispersion within the refractive element. For example, the refractive index of a lens element may vary depending on the wavelength of the incident light. Since the focal length of a lens can depend on the refractive index, the variation in refractive index may affect focusing. The refractive element causing chromatic aberration can be a lens, such as a biconcave lens, and can be a single-focus or multi-focus implantable lens, such as a dual-focus or triple-focus lens with extended depth of focus. The refractive element can have a basic (i.e., intrinsic) LCA of up to about 1 D, or alternatively, a basic LCA of less than 0.25 D. LCA is measured at both extremes of the light spectrum (e.g., 450 nm and 650 nm) as the difference between the nominal powers of the refractive element, e.g., of a lens, such as, LCA = P(λ2) - P(λ1) can be determined, where λ1 and λ2 can be different optical wavelengths (e.g., 450 nm and 650 nm), and for a diffractive element, LCA may depend on the design wavelength λ0, e.g., 550 nm, and P0 which is the (refractive) power of the diffractive element at the wavelength λ0. LCA can be measured, for example, by measuring P(λ1), P(λ2), or can be estimated based on the wavelength. The power in diopters (D) is the reciprocal of the focal length of a refractive element, e.g., a lens, measured in a specific medium with a given refractive index (e.g., in vivo, especially in the natural position, e.g., when measured in the eye, it is a medium such as aqueous humor with n = 1.336, or, for example, in vitro, especially when measured in immersion, it is a balanced salt solution). (Longitudinal) chromatic aberration may depend on the Abbe number of the material used. The Abbe number or V-number of a (transparent) material is approximately a measure of the dispersion of the material (i.e., the change in refractive index with respect to the wavelength of the incident light), and a higher V-value can indicate lower dispersion. The (IOL) refractive element can have an Abbe number of 30 to 60, especially 40 to 50, e.g., 42 or 46, and can be made from a material with an Abbe number of 30 to 60, especially 40 to 50, e.g., 36, 42, 46, or 55. The refractive element can have a basic (refractive) power or nominal power range of 0 D to 40 D, especially 10 D to 30 D, e.g., 20 D to 30 D. The refractive element that causes chromatic aberration can have a central thickness of up to 2 mm, e.g., 1 mm, where the central thickness is the thickness of the refractive element along its optical axis, e.g., when the refractive element is a lens, it is the thickness along the axis about which the refractive element can be rotationally symmetric. The refractive element can have a refractive index greater than 1, preferably at least 1.01 or at least 1.3 and / or at most 3, more preferably at least 1.4 and / or at most 2, especially (about) 1.5, e.g., 1.49 or 1.52, and, for example, the refractive element can be made from a material having a refractive index greater than 1, preferably at least 1.01 and / or at most 3, more preferably at least 1.3 and / or at most 2, especially (about) 1.5, e.g., 1.49 or 1.52.The refractive element can have a refractive index higher than the refractive index at the center of the eye, for example, higher than 1.336. The described refractive index relates to a light wavelength of 589 nm. The refractive element that causes chromatic aberration can be made from an optical material (such as a biocompatible material), for example, an amorphous or single-crystalline material such as PMMA, silicone, acrylate, etc. For example, the refractive element can include or be made from materials such as polymethyl methacrylate (PMMA), hydrophobic acrylic resins (such as phenylethyl methacrylate (PEMA) and phenylethyl acrylate (PEA)), hydrophilic acrylic resins (such as polyhydroxyethyl methacrylate (pHEMA)), and / or silicone (such as polydimethylsiloxane (PDMS)). The refractive element can exhibit a convex surface (structure), for example, a biconvex shape, such as a biconvex lens. In particular, the refractive element can cause a chromatic aberration where the distance between the foci for red light and blue light is 1 - 2 mm when measured in immersion (for example, as described above), and / or 0.4 - 0.6 mm when measured in the natural position or within the eye.

[0018] An element that promotes an increase in chromatic aberration (or an excess, excessive, or excessive amount of chromatic aberration) can be, for example, an element that increases chromatic aberration with respect to the (intrinsic) chromatic aberration of a refractive element, for example, with respect to the chromatic aberration exhibited by a refractive element. The chromatic aberration can be longitudinal chromatic aberration (LCA). For example, an element that promotes an increase in chromatic aberration can be an element that increases longitudinal chromatic aberration. Particularly at light wavelengths of 450 to 650 nm, the (longitudinal) chromatic aberration can increase by, for example, 1D, 2D, 3D, 3.5D or more to about 4D. For example, LCA may depend on the material and (optical) power of an embeddable lens, and / or a refractive element, and / or an element that promotes an increase in chromatic aberration. The increase in LCA can be an increase by a fixed value (for example, from a base power of 0.25 to 3 or 4D). For example, an element that promotes an increase in chromatic aberration can increase the distance between foci at different light wavelengths, for example, by further separating the foci at different light wavelengths, and can depend on the lens power and Abbe number of a refractive element, for example, increase the distance between foci (for example, focal planes) at red light (for example, a wavelength of 650 nm) and blue light (for example, a wavelength of 450 nm). For example, the distance between foci at red light and blue light can increase to at least 5 or 6 mm, or at least 9 mm, for example, up to 6 to 12 mm or 13 mm, for example, up to about 6.8 or 11.4 mm, under standard indoor conditions (for example, a temperature of 20 °C (293.15 K), an absolute pressure of 1 atm (101.325 kPa), a dry air atmosphere). Preferably, the distance between the focus at red light (for example, at 656 nm) and the focus at blue light (for example, at 486 nm) can be between 5 mm and 10 mm when measured in immersion with a refractive index of 1.333 (i.e., the refractive index of the medium surrounding the lens during measurement), and / or the distance between the focus at red light (for example, at 656 nm) and the focus at blue light (for example, at 486 nm) can be between 0.8 mm and 1.3 mm when measured in the natural position (for example, in the eye). Therefore, the chromatic focus shift between 656 nm and 486 nm can be 5 to 10 mm in immersion and 0.8 to 1.3 mm in the natural position.For purposes of comparison, the color shift between 656 nm and 486 nm of the refractive element can be about 1 - 2 mm (in immersion), and / or about 0.5 mm in the natural position. For example, the refractive element can cause chromatic aberration with a distance between foci for red and blue light of 1 - 2 mm when measured in immersion, and / or 0.4 - 0.6 mm when measured in the natural position. The element that promotes an increase in chromatic aberration can be of any suitable material (e.g., biocompatible material), for example, any of the materials described for the refractive element that causes chromatic aberration, for example, can include or can consist of the same material as the refractive element that causes chromatic aberration or a biocompatible material (e.g., can be made of such a material). For example, the refractive element that causes chromatic aberration and the element that promotes an increase in chromatic aberration can include the same material or different materials or can consist of the same material or different materials (e.g., can be made of the same material or different materials). The element that promotes an increase in chromatic aberration can be attached to the rear or front surface of the refractive element, can be placed on the rear or front surface of the refractive element, or can be formed on the rear or front surface of the refractive element. The element that promotes an increase in chromatic aberration can have a rear surface that coincides with the rear or front surface of the refractive element, or can be made smaller, for example, limited to a central lens area, for example, at a diameter of 3 mm - 4 mm. This can further enable improvement in photopic and scotopic vision.

[0019] For example, in the treatment of pseudophakic patients or in the treatment of presbyopia without removing the natural lens, for example, when expanding the depth of focus for a monofocal lens, it has been unexpectedly found that it can be beneficial to increase chromatic aberration using an element that promotes an increase in chromatic aberration, contrary to the standard approach of minimizing chromatic aberration. For example, an increase in chromatic aberration can achieve a long focal shift, which can lead to an expansion of the patient's visual field in polychromatic light. Thus, the implantable lens according to the first exemplary aspect can extend the focus by incorporating various light wavelengths from the visible range, enabling better vision at different distances for patients after cataract surgery.

[0020] The implantable lens according to the first exemplary embodiment can be made completely independent of the pupil. This cannot be achieved, for example, in refractive power-enhanced monofocal lenses that may use the central part of the lens to induce defocus. The implantable lens according to the first exemplary embodiment can further be made more resistant to unexpected postoperative refraction due to the extension of the multi-color focus. Therefore, the implantable lens according to the first exemplary embodiment can improve the patient's visual range while minimizing the side effects associated with standard methods of light splitting. Also, since, for example, materials with a lower Abbe number, such as more cost-effective materials, can be used, the implantable lens according to the first exemplary embodiment can be made more cost-effective than, for example, multifocal lenses and can be manufactured cost-effectively.

[0021] According to the first exemplary embodiment of the implantable lens according to the first exemplary aspect, the increase in chromatic aberration is an increase of at least 2-fold, preferably at least 3-fold, particularly between 3 and 7-fold (for example, in situ or in immersion). It has been found that in order to improve the achieved effect, it may be preferable to increase the chromatic aberration more. However, an increase exceeding 7-fold may not be achievable with cost-effective materials. This multiple can be the multiple compared to the chromatic aberration caused by the refractive element, which can be measured in immersion, for example, the chromatic aberration caused only by the dispersion of the refractive element, for example, based on a refractive lens.

[0022] According to a second exemplary embodiment of an implantable lens according to the first exemplary aspect, the refractive element has a rear surface and a front surface, and the rear surface and / or the front surface has an aspherical or spherical shape. The aspherical or spherical shape can improve the optical properties of the refractive element, enable accurate adaptation of the refraction of the refractive element, and further improve the patient's visual range while minimizing side effects. If it is a spherical shape (for example, the surface profile of the refractive element, such as the lens, is a part of a sphere) or a cylindrical shape (for example, the surface profile of the refractive element, such as the lens, is a part of a cylinder), the manufacturing can be made easier and more cost-effective. If it is an aspherical shape (that is, a non-spherical shape, for example, a lens whose surface profile is not a part of a sphere or a cylinder), spherical aberration can be avoided, reduced or eliminated, and therefore, the patient's visual range can be further improved while minimizing side effects.

[0023] The element that promotes an increase in chromatic aberration can have an Abbe number of 30 to 60, particularly 40 to 50, such as 42 or 46, and can be made of a material with an Abbe number of 30 to 60, particularly 40 to 50, such as 36, 42, 46 or 55.

[0024] The rear surface and the front surface can be defined by the direction of incident light that travels into the eye from the outside when the lens is implanted. The rear surface is the surface through which the incident light first passes when the lens is implanted, that is, the surface facing the outside or the cornea, while the front surface faces the inside of the eye, such as the vitreous retina chamber or the retina, when the lens is implanted.

[0025] According to a third exemplary embodiment of an implantable lens according to the first exemplary aspect, the element that promotes an increase in chromatic aberration includes a diffraction structure, and in particular, the diffraction structure is a Fresnel structure, particularly a kinoform lens structure.

[0026] The diffraction structure can be, for example, an optical structure specially designed to promote the diffraction of incident light. The diffraction structure can utilize a first diffraction order and a second diffraction order, and / or (e.g., partially) a third diffraction order. The first diffraction order and / or the second diffraction order can be positive or negative, i.e., can have positive or negative signs respectively. Preferred examples of the diffraction structure can be a Fresnel structure, or more preferably a kinoform lens structure, which can enable more cost-effective production and improved compatibility with the needs of patients. The kinoform lens structure can enable further improvement in reducing chromatic aberration and further improve the patient's visual range while minimizing side effects. The kinoform lens structure can further achieve an improvement in focusing efficiency. For example, if it is a kinoform made of a non-absorbing but refractive material, it can have 100% focusing efficiency and further improve the patient's visual range while minimizing side effects. The diffraction structure can be attached to the rear surface or the front surface of the refractive element, can be installed on the rear surface or the front surface of the refractive element, or can be formed on the rear surface or the front surface of the refractive element. The diffraction structure can have a rear surface that coincides with the rear surface or the front surface of the refractive element, or can be made smaller, for example, limited to a central lens area, for example, in the range of 3 mm to 4 mm in diameter. This can further enable the improvement of mesopic and scotopic vision.

[0027] The Fresnel structure can be or can include a kinoform lens structure. The kinoform lens is a diffractive / refractive optical system and can utilize both modes, thereby ensuring maximum efficiency. The kinoform lens structure can have a (general) parabolic surface profile (e.g., surface relief profile). The kinoform lens structure can exhibit zones (e.g., extending from the minimum height to the maximum height within the structure) and step heights (i.e., the maximum height difference within the zone). The zones within the kinoform lens structure can take the form of circular annular rings. On the other hand, these zones can occupy other shapes such as bars (as in a conventional spectroscopic diffraction grating) and ellipses (for generating different focal lengths at different angular orientations around the optical axis). Further, multiple groups of zones can be arranged within a two-dimensional cell-like array, and each cell functions as an individual optical element. Within each zone, the theoretically optimal depth profile can be a smooth curve continuously extending from the highest region to the lowest region. On the other hand, for ease of manufacturability, it can be approximated to the optimal profile as a series of steps (phase levels) each having a constant depth. The surface relief profile t(r) can be approximately determined from the relationship t(r)=[λ / 2π(μ - 1)][Φ(r)]2π, where λ is the light wavelength, μ is the refractive index of the optical material (of the surface relief profile), and [Φ(r)]2π is the phase function Φ(r) with 2π as the normal. The kinoform lens structure can exhibit any phase profile, for example, an interference pattern defined by any two coherent point light sources on any surface. Any two-dimensional phase profile defined by any polynomial can be added to this interference pattern. In particular, the kinoform lens structure can be described as an interference pattern generated on a plane perpendicular to the optical axis defined by two points where one point is at infinity. The kinoform lens structure can be generated by etching or machining the raised portions into the surface, for example, into the (rear and / or front) surface of a refractive element, for example, by step approximation or gray-scale direct milling IBL.The kinoform lens structure can be made from optical materials, such as amorphous or single crystal materials like PMMA, silicone, acrylate, etc. For example, the kinoform lens structure can comprise or be made from plastics such as polymethyl methacrylate (PMMA), hydrophobic acrylic resins (such as phenylethyl methacrylate (PEMA) and phenylethyl acrylate (PEA)), hydrophilic acrylic resins (such as polyhydroxyethyl methacrylate (pHEMA)), and / or silicone (such as polydimethylsiloxane (PDMS)).

[0028] The kinoform lens structure can be composed of or can include a continuous "sawtooth" surface profile that can promote light divergence, as can be further detailed below by way of example. In particular, the (negative) kinoform lens structure can exhibit a diffractive (surface) profile that has no (outward) central bulge (that can be at least partially superposed on the surface of the refractive element), for example, along the optical axis with respect to the refractive element, since it has a minimum at the center, and the distance between the "sawtooth" maxima can decrease with the distance from the center. For example, the kinoform lens structure may have a lower central zone for the first diffractive step (with respect to the center).

[0029] The kinoform lens structure can be a Fresnel phase zone plate structure or can include a Fresnel phase zone plate structure. The Fresnel phase zone plate structure can have an appearance similar to that of a Fresnel lens structure. The Fresnel phase zone plate structure can include several concentric rings having a certain zone radius (corresponding to each zone). The Fresnel phase zone plate structure may appear as a series of sawtooth-shaped ridges when viewed from the side. The Fresnel phase zone plate structure can rely on diffraction rather than refraction and can have many more zones (e.g., 10 - 40 or 15 - 30) and a much smaller height (i.e., step height) difference between adjacent zones compared to a Fresnel lens. The step height within a zone can correspond to, for example, a phase change of 2π (one wavelength). The step height can be, for example, at least 0.1 μm, at least 0.6 μm, or at least 1 μm, and / or at most 10 μm, and for example, the step height can be 6.7 μm. For example, the Fresnel phase zone plate structure can include 10 - 40 or 15 - 30 zones (in the form of concentric rings, for example, around the optical axis of a certain / its refractive element). The minimum zone radius can be at least 0.4 mm, particularly at least 0.55 mm, or at least 0.76 mm, and / or at most 1 mm. For example, LCA may depend on the material and (optical) power of the implantable lens, and / or the refractive element, and / or the element that promotes an increase in chromatic aberration. The increase in LCA can be an increase by a fixed value (e.g., from a base power of 0.25 to 3D or 4D). A unique kinoform (lens) structure can be designed for an implantable lens having a refractive element with a base power between 0 - 40D. For example, the kinoform lens structure can be formed on the rear surface and / or the front surface of the refractive element, or within the rear surface and / or the front surface. The kinoform lens structure can extend from the center of the refractive element to its edge, for example, from the center of the rear surface or the front surface to the edge of the rear surface or the front surface, respectively.Alternatively, the kinoform lens structure can extend from the center of the refractive element to a distance smaller than the distance between the center and the edge of the refractive element, for example, from the center of the rear or front surface to a distance smaller than the maximum (radial) distance from the center of the rear or front surface to the edge of the rear or front surface (respectively), for example, to a (radial) distance of 1.5 to 2 mm (e.g., 2.25 mm) (measured from the center). Therefore, the kinoform lens structure can be limited, for example, to the central area of the surface of the refractive element, for example, at a diameter of 3 mm to 4 mm / 4.5 mm, which can further enable the improvement of mesopic and scotopic vision.

[0030] According to a further exemplary embodiment of the implantable lens according to the first exemplary aspect, the refractive element has a rear surface and a front surface, and the diffraction structure is on the rear surface and / or on the front surface. In this way, the diffraction structure can be advantageously installed and / or distributed on the surface of the refractive element, and thus, the visual range of the patient can be further improved while minimizing side effects.

[0031] According to a further exemplary embodiment of the implantable lens according to the first exemplary aspect, the diffraction structure is, in particular, a negative diffraction structure having a power of at most -1D, preferably, the power is between -1D and -11D (i.e., at least -11D and / or at most -1D), more preferably at least -8D and / or at most -3D, for example, -7D. In particular, a negative diffraction structure having a power of at most -1D can further improve the visual range of the patient while minimizing side effects. On the other hand, a power of less than -11D cannot be produced cost-effectively and may generate further side effects.

[0032] According to a further exemplary embodiment of the implantable lens according to the first exemplary aspect, the diffraction structure includes a diffraction profile. In particular, the diffraction profile extends from the first Fresnel zone of the diffraction structure to the edge of the refractive element, or the diffraction profile extends from the center of the refractive element to the edge of the refractive element. The diffraction profile can be a profile that causes diffraction of light. The diffraction profile can be a profile formed in the rear surface and / or the front surface, for example, by etching or laser shaping. The first Fresnel zone can be centered, for example, at the center of the rear surface or the front surface. For example, the axis that makes the first Fresnel zone rotationally symmetric can be the optical axis of the refractive element. The edge can be, for example, the edge of the front surface or the rear surface. Using a diffraction profile, for example, a kinoform profile (i.e., a diffraction profile having a kinoform lens structure), can further improve the patient's visual range while minimizing side effects.

[0033] The diffraction profile can have a minimum value at the center and thus can be a continuous "sawtooth" surface profile without, for example, an outward central bulge, and the distance between the "sawtooth" maxima can decrease with the distance from the center.

[0034] According to a further exemplary embodiment of the implantable lens according to the first exemplary aspect, together with the refractive element and the element that promotes an increase in chromatic aberration, it includes or forms such a diffractive-refractive zone that is (substantially) centered on the center of the refractive element. In particular, the diffractive-refractive zone has a diameter ranging from 3 mm to 4.5 mm (and for example, the surface of the refractive element on which the diffractive-refractive zone is formed can have a diameter of 5.5 to 7 mm). The diffractive-refractive zone can be formed, for example, by a diffractive profile, and can be formed, for example, by a refractive element (such as a surface having a concave or convex form) and a diffractive profile formed, for example, etched, into the surface of the refractive element. The diffractive-refractive zone can be formed, for example, by a kinoform profile. The center of the refractive element can be defined by the optical axis of the implantable lens. The optical axis can be an axis that (substantially) exhibits the rotational symmetry of the implantable lens and / or the refractive element. The optical axis can, for example, pass through the centers of curvature of each surface of the implantable lens and / or the refractive element and can coincide with the axis of rotational symmetry. The optical axis can, for example, coincide with the mechanical axis of the implantable lens and / or the refractive element. The diffractive-refractive zone can enable a further improvement in the patient's visual range while minimizing side effects.

[0035] A certain / part of the surface of the refractive element not covered by the diffractive-refractive zone, for example, the outer zone, can be considered to have only refractive properties without the diffractive effect being promoted. The outer zone can be a ring on each surface of the refractive element with an inner diameter of 3 to 4.5 mm and an outer diameter of 5.5 to 7 mm, or a ring extending to the edge. The outer zone can enable refractive power compensation and further improve the patient's visual range while minimizing side effects.

[0036] According to a further exemplary embodiment of the implantable lens according to the first exemplary aspect, the diffraction structure utilizes a first (e.g., positive or negative) diffraction order and / or a second (e.g., positive or negative) diffraction order. For example, the implantable lens and / or refractive element can utilize the simultaneous action of both the first order and the second order, such as in the case of a dual-focus or triple-focus lens where the first order and the second order are used simultaneously, or when including such a lens. This enables a further improvement in the patient's visual range while minimizing side effects.

[0037] According to a further exemplary embodiment of the implantable lens according to the first exemplary aspect, the diffraction element and the element that promotes an increase in chromatic aberration direct light to the same focus with respect to a determined light wavelength, for example, a wavelength of 550 nm, 555 nm, or 546 nm. This enables a further improvement in the patient's visual range while minimizing side effects.

[0038] According to a further exemplary embodiment of the implantable lens according to the first exemplary aspect, the implantable lens has a monochromatic modulation transfer function (MTF) of 0.43 or more (e.g., higher than that) at 100 lp / mm, preferably a monochromatic modulation transfer function (MTF) of 0.5 or more (e.g., higher than that) at 100 lp / mm, more preferably 0.6 or more. The implantable lens can meet the optical quality standards of a single-focus lens as defined, for example, in standard ISO11979-2:2014. Such an implantable lens can enable an improvement in optical performance. This enables a further improvement in the patient's visual range while minimizing side effects.

[0039] According to a further exemplary embodiment of the implantable lens according to the first exemplary aspect, the refractive element has a nominal power range of -5D to 40D or 0D to 40D, particularly 20D to 30D. This enables a further improvement in the patient's visual range while minimizing side effects.

[0040] According to a further exemplary embodiment of the implantable lens according to the first exemplary aspect, the element that promotes an increase in chromatic aberration increases the chromatic aberration by at least 1D, preferably by at least 2D, in the spectral range from 450 nm to 650 nm. For example, the element that promotes an increase in chromatic aberration can increase the chromatic aberration of the pseudophakic eye by at least 1D, preferably by at least 2D, in the spectral range from 450 nm to 650 nm. This can enable a further improvement in the patient's visual range while avoiding or minimizing side effects.

[0041] According to a further exemplary embodiment of the implantable lens according to the first exemplary aspect, the element that promotes an increase in chromatic aberration and the refractive element are made of the same material. In particular, for example, by forming the element that promotes an increase in chromatic aberration on or within the refractive element, the element that promotes an increase in chromatic aberration and the refractive element form an integral unit. This can enable a further improvement in the patient's visual range while minimizing side effects.

[0042] According to a further example of the implantable lens according to the first exemplary aspect, the kinoform lens structure includes a serrated surface profile superimposed in particular on the front and / or rear surface of the refractive element, and the kinoform lens structure can optionally have a lower central zone with respect to the first diffraction step.

[0043] According to a further example of the implantable lens according to the first exemplary aspect, the serrated surface profile exhibits a minimum value at the center (i.e., at a radius of 0). In particular, the distance between the maximum values at which the serrated surface profile reaches the step height decreases with the distance from the center. For example, when the serrated surface profile is centered on the center of the refractive element, the center can correspond to the center of the refractive element. In order to take into account any irregularities promoted by the surface structure (e.g., convex surface) of the refractive element, the maximum and minimum values can be determined with respect to a baseline corresponding to each surface of the refractive element.

[0044] According to a second exemplary aspect, the above object is solved by a method for manufacturing an embeddable lens according to the first exemplary aspect, the method including the step of etching and / or machining an element that promotes an increase in chromatic aberration on the front surface and / or the rear surface of the refractive element.

[0045] According to a further exemplary embodiment of the implantable lens according to the first exemplary aspect, it can be a hybrid refractive-diffractive intraocular lens. For example, the implantable lens can have a rear surface and a front surface, and one or both of these surfaces can be, for example, aspherical or have a spherical shape, and one or both have, for example, a Fresnel or kinoform lens structure that provides the refractive effect of a negative (diverging) lens, so that, for example, the excess positive refractive power of the basic refractive element is compensated, while both the diffractive and refractive structures contribute to a single focal point. The implantable lens can include or consist of a refractive element having a refractive dispersion effect and a Fresnel or kinoform lens structure having a diffractive dispersion effect. The (Fresnel) lens power of the Fresnel lens or kinoform lens structure is, for example, in the range of -1D to -11D. The (hybrid) refractive-diffractive intraocular lens can have a nominal power range of about 0D to about 40D. The implantable lens can be designed, for example, by combining refractive chromatic aberration and diffractive chromatic aberration, to increase the chromatic aberration of the pseudophakic eye by about 1D in the spectral range from 450 nm to 650 nm. The intraocular lens according to claim 2 increases the chromatic aberration of the pseudophakic eye by about 2D in the spectral range from 450 nm to 650 nm by combining refractive chromatic aberration and diffractive chromatic aberration. The implantable lens, for example, a refractive-diffractive intraocular lens, can utilize, for example, a negative diffractive element that is the first (for example, positive or negative) diffraction order, and / or a negative diffractive element that is the second (for example, positive or negative) diffraction order. The implantable lens, for example, a refractive-diffractive intraocular lens, can have a diffraction profile that extends from the first Fresnel zone to the edge of the lens. The implantable lens, for example, a refractive-diffractive intraocular lens, can have a diffraction-refractive zone in the center of the lens with a zone diameter ranging from 3 mm to 4.5 mm, and a purely refractive outer zone that compensates for the refractive power. The implantable lens, for example, a refractive-diffractive intraocular lens, can have a monochromatic MTF of 0.43 or more at 100 lp / mm.

[0046] The exemplary aspects and exemplary embodiments disclosed are capable of achieving an expansion of depth of focus, for example, to meet the needs of pseudophakic patients after cataract surgery, particularly with respect to improving a patient's visual range with minimal or no side effects.

[0047] The features and exemplary embodiments described above can be equally related in different ways.

[0048] Other features and advantages will become apparent from the following detailed description when considered in conjunction with the accompanying drawings.

Brief Description of the Drawings

[0049]

Figure 1

Figure 2

Figure 3

Figure 4A

Figure 4B

Figure 5A

Figure 5B

Figure 6A

Figure 6B

Figure 7A

Figure 7B

Figure 8

Figure 9A

Figure 9B

Figure 10A

Figure 10B

Figure 10C

Figure 11

Figure 12A

Figure 12B

Mode for Carrying Out the Invention

[0050] The following description is for enhancing understanding and is to be understood as complementing the description provided in the above Summary chapter of this specification and read together with this description. Some aspects may have different terms than those provided, for example, in the above description. Nevertheless, those skilled in the art will understand that, for example, by becoming more specific, those terms refer to the same subject matter. For example, a diffractive structure may be referred to as a diffraction grating. The basic (refractive) power may be referred to as the (nominal) power.

[0051] FIG. 1 shows an exemplary implantable lens 100 according to a first exemplary embodiment, including a refractive element 101 that causes chromatic aberration and an element 102 that promotes an increase in chromatic aberration. The element 102 that promotes an increase in chromatic aberration includes a diffractive structure 102, particularly a kinoform lens structure 102. The refractive element 101 has a front surface 103, and the diffractive structure 102 is on the front surface 103 (centered on the front surface), and the axis that makes the kinoform lens structure rotationally symmetric is the optical axis of the refractive element 101. The refractive element 101 and the element 102 that promotes an increase in chromatic aberration together include a diffractive-refractive zone 104 centered on the center of the refractive element 101. The diffractive structure 102 is a negative diffractive structure 102. A part of the surface 103 of the refractive element 101 not covered by the diffractive-refractive zone 104 is, for example, an external zone 105 that can be simply refractive without promoting a refractive effect and / or without a diffractive effect. Alternatively, the diffractive structure 102 includes a diffractive profile that extends from the first Fresnel zone of the diffractive structure to the edge 106 of the refractive element, or the diffractive profile extends from the center of the refractive element to the edge 106 of the refractive element. The implantable lens 100 can be an IOL 100, and the refractive element 101 can be a (e.g., plastic) lens 101 with side struts 107 (e.g., support portions 107) for holding the lens in place within the capsular bag of the intraocular lens in the eye.

[0052] FIG. 2 shows a case where an IOL not according to the first exemplary embodiment having a refractive element 101 that causes chromatic aberration is implanted in an eye 200. Due to the chromatic aberration caused by the refractive element 101, light 203 of different wavelengths lambda_1, wavelength lambda_2, and wavelength lambda_3 is directed to different foci or focal points 204, 205, 206. For example, blue light 203 with a wavelength of lambda_1, for example 450 nm, can be directed to the focus 204, green light 203 with a wavelength of lambda_2, for example 550 nm, can be directed to the focus 205, and red light 203 with a wavelength of lambda_3, for example 650 nm, can be directed to the focus 206. The optical axis 207 coincides with the axis of rotational symmetry of the refractive element 101.

[0053] Figure 3 shows an exemplary implantable lens 100 according to a first exemplary embodiment, which includes a refractive element 101 that causes chromatic aberration (which can be the refractive element shown in FIG. 2) and an element 102 that promotes an increase in chromatic aberration. The element 102 that promotes an increase in chromatic aberration includes a diffractive structure 102, particularly a kinoform lens structure 102. The refractive element 101 has a front surface 108 and a rear surface 103. The diffractive structure 102 is located on the rear surface 103 and centered on the center of the rear surface 103, that is, centered on the rear surface 103. The axis 207 about which the diffractive structure 102, particularly the kinoform lens structure 102, is rotationally symmetric coincides with the optical axis 207 of the refractive element 101. The diffractive structure 102 can be a negative diffractive structure 102. The element 102 that promotes an increase in chromatic aberration, for example, the diffractive structure 102, can cover (almost) the entire rear surface 103. For example, this structure can extend from the center of the refractive element 101 to the edge 106 of the refractive element 101. The exemplary implantable lens 100 is implanted within the eye 200. Due to chromatic aberration, light 203 of different wavelengths lambda_1, lambda_2, and lambda_3 is directed to different foci or focal points 301, 302, 304. For example, blue light 203 with a wavelength of lambda_1, for example, 450 nm, can be directed to the focal point 301, and red light 203 with a wavelength of lambda_3, for example, 650 nm, can be directed to the focal point 304. The optical axis 207 coincides with the rotational symmetry axis of the refractive element 101. The implantable lens 100 is implanted within the lens capsule in the eye 200 behind the cornea 201 and the iris 202 in this example. The refractive element and the element that promotes an increase in chromatic aberration direct light to the same focus with respect to a determined light wavelength, for example, the design wavelength, for example, 550 nm. The element 102 promotes an increase in chromatic aberration with respect to the (intrinsic) chromatic aberration of the refractive element 101.For example, the focal point of the refractive element 101 for green light, for example, with a design wavelength lambda_2, for example 550, 555, or 456 nm, can be the same as that of the refractive element 101 alone (compared with FIG. 2). On the other hand, the focal point for blue light having a wavelength lambda_1 of 450 nm can be shifted closer to the refractive element 101 (with respect to the focal point of the refractive element 101 alone at the lambda_3 wavelength), while the focal point for red light having a wavelength lambda_3 of 650 nm can be shifted away from the refractive element due to the element 102 promoting an increase in chromatic aberration. Thus, the distance between the focal points for red light and blue light increases with respect to the distance between the focal points for red light and blue light of the refractive element 101 (which is alone and does not have the element 102 that promotes an increase in chromatic aberration).

[0054] An implantable lens according to a first exemplary aspect, for example an ophthalmic lens, for example an IOL, promotes excessive longitudinal chromatic aberration (LCA) and can expand the depth of focus (DoF) of the eye, for example after removing the crystalline lens and implanting the (IOL). Embodiments of the implantable lens according to the first exemplary aspect can increase LCA through refractive and diffractive principles and can be applied in a monofocal IOL, for example a standard monofocal IOL. On the other hand, this application can also be extended to multifocal IOLs to eliminate the visual quality gap observed between the designed focal points seen in modern technologies. The implantable lens according to the first exemplary aspect can be applicable to a standard capsular implant, as well as auxiliary IOLs or phakic IOLs.

[0055] For example, to correct aphakia after cataract surgery or refractive lens exchange, achieve good distance vision, and expand the DoF of the eye, embodiments of the implantable lens according to the first exemplary aspect can be used. Such embodiments can be, for example, hybrid lenses, and the hybrid lenses include, for example, the basic (refractive) power of the refractive element and a diffraction grating of an element that promotes an increase in chromatic aberration disposed on the front surface, rear surface, or both surfaces of the refractive element.

[0056] In one example, the refractive element (e.g., a (biconvex) lens) has a pattern of diffractive grooves (e.g., a kinoform lens structure) located rearwardly, e.g., on the rear surface of the refractive element or the lens. Such a diffraction grating can have a negative lens refractive effect. Thus, in order to compensate for the reduced power, the basic refractive power (e.g., of the refractive element) can be selected to be higher than the nominal power. This exemplary embodiment of the implantable lens according to the first aspect can increase the LCA while maintaining the position of the blue focus more forward with respect to the central wavelength (i.e., the design wavelength, e.g., 550 nm) compared to the red focus located more rearwardly, thereby making it equivalent to natural conditions. On the other hand, other exemplary embodiments that promote an (excessive) negative LCA with a lower basic power and a positive refractive power of the diffraction grating can also be used.

[0057] In a further exemplary embodiment of the implantable lens according to the first exemplary aspect, the exemplary refractive element has a rear surface and a front surface having a spherical shape and thus resembles a biconvex lens. The exemplary refractive element has an optical power or nominal power of 20D. The exemplary element that promotes an increase in chromatic aberration is the exemplary kinoform lens structure on (formed on) the rear surface of the exemplary refractive element, and the exemplary kinoform lens structure has a central thickness of, for example, 1 mm. The exemplary kinoform lens structure has 15 zones (e.g., consists of 15 zones). The exemplary refractive element and the exemplary kinoform lens structure together form an exemplary diffractive-refractive zone centered on the center of the exemplary refractive element. The exemplary element that promotes an increase in chromatic aberration and the refractive element are made of the same exemplary material having an Abbe number of 46 and a refractive index of 1.50 and form an integral unit.

[0058] For example, an implantable lens was assembled using a material having a refractive index of 1.50 and an Abbe number of 46. Assuming a central lens thickness of 1 mm, the nominal power was set to +20 D. To test the optical quality and defocus tolerance of the proposed embodiment, a model eye can be constructed in ZEMAX OpticStudio (registered trademark) (manufactured by Radiant Zemax LLC) in accordance with ISO 11979. For such tests, optical simulations can be performed in polychromatic light spectrally weighted to correspond to the CIE photopic luminance function in the range of 450 to 650 nm.

[0059] In a further exemplary embodiment of the implantable lens according to the first exemplary aspect, the exemplary refractive element has a rear surface and a front surface having a spherical shape, and thus resembles a biconvex lens. The exemplary refractive element has a basic (optical) power or nominal power of 23.75 D and has a central thickness of, for example, 1 mm. An exemplary element that promotes an increase in chromatic aberration is an exemplary kinoform lens structure that is on (formed on) the rear surface of the exemplary refractive element (the exemplary (radial) profile thereof is represented in FIGS. 4A / 4B), and the exemplary kinoform lens structure has an (optical) power of -3.75 D. The exemplary kinoform lens structure has 15 zones (consisting of, for example, 15 zones), and these 15 zones have a minimum zone radius of 0.76 mm (see FIG. 4A) and a step height of 6.7 μm. The exemplary refractive element and the exemplary kinoform lens structure together include an exemplary diffractive-refractive zone that is centered on the center of the exemplary refractive element. The exemplary kinoform lens structure utilizes a second diffraction order (m = 2). The exemplary element that promotes an increase in chromatic aberration and the refractive element are made of the same exemplary material having, for example, an Abbe number of 46 and a refractive index of 1.50, forming an integral unit. In the exemplary element that promotes an increase in chromatic aberration, the exemplary increase in chromatic aberration is twice the increase (in chromatic aberration caused by the refractive element and the eye). The distance between the foci of light between 486 and 656 nm can increase up to 5654 μm when measured in immersion where the surrounding medium has a refractive index of 1.336, and up to 880 μm when measured in the eye / in situ. For the refractive element (without the element that increases chromatic aberration), the distance between the foci of light between 486 and 656 nm can be 1364 μm when measured in immersion with a refractive index of 1.336 for the surrounding medium, and 479 μm when measured in the eye / in situ.

[0060] For example, a positive refractive base with a power of 23.75 D was combined with a negative Fresnel lens (-3.75 D). As a result, the chromatic aberration of the pseudophakic eye was effectively doubled. The second diffraction order (m = 2) was used, and the diffractive surface consisted of 15 Fresnel zone plates with a minimum zone radius of 0.76 mm (see FIG. 6A). When m = 2 was selected, the step height became 6.7 μm. This can ensure maximum efficiency. On the other hand, if different (e.g., positive or negative) diffraction orders should be used, the step height can be adjusted accordingly. For example, when m = 1 is selected, the first Fresnel zone radius can be 0.54 mm, and the step height can be 0.003 mm or 0.0033 mm. This exemplary embodiment represents a full diffractive design in which the diffraction grating is disposed on the back surface. There are also other embodiments with a diffraction grating limited to the central lens area (e.g., 3 mm or 4 mm) that can enable improvements in mesopic and scotopic vision. This exemplary embodiment can be assembled using a material having a refractive index of 1.50 and an Abbe number of 46. Assuming the central lens thickness is, for example, 1 mm. The chromatic focal shift between 486 nm and 656 nm can be 5654 μm when measured in immersion (refractive index of the surrounding medium 1.336). The chromatic focal shift between 486 nm and 656 nm can be 880 μm when measured in the eye / in the natural position. For a lens without additional LCA, the chromatic shift can be 1364 μm (immersion) and 479 μm (natural position).

[0061] Figure 4A shows an exemplary diffractive profile of an element that promotes an increase in chromatic aberration, particularly a kinoform lens structure, for an embeddable lens according to a first exemplary embodiment, which can provide further details by way of the example above. The step height was 6.7 μm (see the vertical axis indicating the sagitta (SAG)). The diffractive profile utilizes a two-fold increase in the longitudinal chromatic aberration of the eye. The diffractive profile is a (continuous) sawtooth surface profile having a minimum value at the center (at a radius of 0 mm). Since the baseline of the diffractive profile can follow the surface of the refractive element, it can be superimposed on the (rear or front) surface of the refractive element. Further, the distance between the "sawtooth" maximum values where the profile reaches the step height decreases with the distance from the center. Figure 4B shows an exemplary phase map (with 2π as the modulus) of this exemplary embodiment.

[0062] For example, the element that promotes an increase in chromatic aberration can be an element that promotes light divergence, and the exemplary diffractive profile shown in Figure 4A can be that of an element that promotes light divergence and has a negative focal length for an embeddable lens according to a first exemplary embodiment, particularly a kinoform lens structure having a lower central zone for the first diffraction step.

[0063] The simulated optical quality in a model eye meets the requirements of the manufacturing standard (ISO 11979-2) for a single-focus lens, which requires that the monochromatic (550 nm) modulation transfer function (MTF) be 0.43 or more at 100 lp / mm. The exemplary embodiment described exceeds this requirement with an MTF value of 0.66, which indicates almost diffraction-limited performance (Figure 5A). Figure 5B shows the polychromatic MTF of the embodiment under consideration.

[0064] Figures 5A and 5B show the modulation transfer function (MTF) levels of an exemplary embodiment in which the longitudinal chromatic aberration in a model eye is increased two-fold. The monochromatic (Figure 5A) and polychromatic (Figure 5B) MTFs (solid lines) up to 100 lp / mm are shown. The dashed line (Figure 5A) shows the minimum (monochromatic) MTF at 100 lp / mm that is acceptable for a single-focus IOL.

[0065] In a further exemplary embodiment of the implantable lens according to the first exemplary aspect, the exemplary refractive element has a rear surface and a front surface having a spherical shape and thus resembles a biconvex lens. The exemplary refractive element has a base (optical) power or nominal power of 27.25 D. An exemplary element that promotes an increase in chromatic aberration is an exemplary kinoform lens that is on (formed on) the rear surface of the exemplary refractive element (the exemplary (radial) profile thereof is shown in FIGS. 6A / 6B), and the exemplary kinoform lens structure has a (optical) power of -7.25 D. The exemplary kinoform lens structure has 30 zones (e.g., consists of 30 zones), and these 30 zones have a minimum zone radius of 0.55 mm (see FIG. 6A) and a step height of 6.7 μm. Together with the exemplary refractive element and the exemplary kinoform lens structure, they form an exemplary diffractive-refractive zone that is centered on the center of the exemplary refractive element. The exemplary kinoform lens structure utilizes a second diffraction order. The exemplary element that promotes an increase in chromatic aberration and the refractive element are made of the same exemplary material having an Abbe number of 46 and a refractive index of 1.50 and form an integral unit. In the exemplary element that promotes an increase in chromatic aberration, the exemplary increase in chromatic aberration is three times the increase (in chromatic aberration caused by the refractive element and the eye). The distance between the foci of light between 486 and 656 nm can increase up to 9722 μm when measured in immersion with a refractive index of 1.336 of the surrounding medium and up to 1247 μm when measured in the eye / in situ. For the refractive element (without the element that increases chromatic aberration), the distance between the foci of light between 486 and 656 nm can be 1364 μm when measured in immersion with a refractive index of 1.336 of the surrounding medium and 479 μm when measured in the eye / in situ.

[0066] For example, a positive refractive base with a power of 27.25 D was combined with a negative Fresnel lens (-7.25 D). As a result, the chromatic aberration of the pseudophakic eye was effectively tripled. The second diffraction order (m = 2) was used, and the diffractive surface consisted of 30 Fresnel zone plates with a minimum zone radius of 0.55 mm (Figure 3). When m = 2 was selected, the step height became 6.7 μm. This can ensure maximum efficiency. On the other hand, if different (e.g., positive or negative) diffraction orders are to be used, the step height can be adjusted accordingly. For example, when m = 1 is selected, the first Fresnel zone radius can be 0.39 mm, and the step height can be 0.003 mm or 0.0033 mm. This exemplary embodiment represents a full diffractive design in which the diffraction grating is disposed on the back surface. There are also other embodiments with a diffraction grating limited to the central lens area (e.g., 3 mm or 4 mm) that can enable improvements in mesopic and scotopic vision. This exemplary embodiment can be assembled using a material having a refractive index of 1.50 and an Abbe number of 46. Assuming the central lens thickness is, for example, 1 mm. The chromatic focal shift between 486 nm and 656 nm can be 9722 μm when measured in immersion (refractive index of the surrounding medium 1.336). The chromatic focal shift between 486 nm and 656 nm can be 1247 μm when measured in the eye / in situ. For a lens without additional LCA, the chromatic shift can be 1364 μm (immersion) and 479 μm (in situ).

[0067] Figure 6A shows an exemplary diffraction profile of an element that promotes an increase in chromatic aberration, particularly a kinoform lens structure, for an embeddable lens according to a first exemplary embodiment, and can provide further details by the above example. The diffraction profile utilizes a three-fold increase in the longitudinal chromatic aberration of the eye. The diffraction profile is a continuous "sawtooth" surface profile having a minimum value at the center (at a radius of 0 mm). The baseline of the diffraction profile is superimposed on the (rear or front) surface of the refractive element to follow the surface of the refractive element. Further, the "sawtooth" maximum value at which the profile reaches the step height decreases with the distance from the center. Figure 6B shows an exemplary phase map (with 2π as the modulus) of this exemplary embodiment.

[0068] For example, the element that promotes an increase in chromatic aberration can be an element that promotes light divergence, and the exemplary diffraction profile shown in Figure 6A is that of an element that promotes light divergence and has a negative focal length for an embeddable lens according to a first exemplary embodiment, particularly, it can be that of a kinoform lens structure with a lower central zone for the first diffraction step.

[0069] The simulated optical quality in a model eye meets the requirements of the manufacturing standard (ISO 11979-2) for a single-focus lens, which requires that the monochromatic (550 nm) modulation transfer function (MTF) be 0.43 or more at 100 lp / mm. The exemplary embodiment described exceeds this requirement with an MTF value of 0.65, which indicates almost diffraction-limited performance (Figure 7A). Figure 7B shows the polychromatic MTF of the embodiment under consideration.

[0070] Figures 7A and 7B show the modulation transfer function (MTF) levels of an exemplary embodiment in which the longitudinal chromatic aberration in a model eye is increased three-fold. The monochromatic (Figure 7A) and polychromatic (Figure 7B) MTFs (solid lines) up to 100 lp / mm are shown. The dashed line (Figure 7A) shows the minimum (monochromatic) MTF at 100 lp / mm that is acceptable for a single-focus IOL.

[0071] In a further exemplary embodiment of the implantable lens according to the first exemplary aspect, the exemplary refractive element has a rear surface and a front surface having a spherical shape, and thus resembles a biconvex lens. The exemplary refractive element has a base (optical) power or nominal power of 23.5D. An exemplary element that promotes an increase in chromatic aberration is an exemplary kinoform lens structure that is located on (formed on) the rear surface of the exemplary refractive element (see the phase map (with 2π as the norm) of FIG. 8), and the exemplary kinoform lens structure has a (optical) power of -3.5D. The exemplary kinoform lens structure has 14 zones (for example, consists of 14 zones), and these 14 zones have a minimum zone radius of, for example, 0.8 mm and a step height of 6 μm. The exemplary element that promotes an increase in chromatic aberration and the refractive element are made of the same exemplary material having an Abbe number of 42 and a refractive index of 1.52, forming an integral unit. In the exemplary element that promotes an increase in chromatic aberration, the exemplary increase in chromatic aberration is twice the increase (in chromatic aberration caused by the refractive element and the eye). For example, a positive refractive base with a power of 23.5D is combined with a negative Fresnel lens (-3.5D). As a result, the chromatic aberration of the pseudophakic eye has effectively doubled. The second diffraction order (m = 2) is used, and the diffractive surface consists of 14 Fresnel zone plates with a minimum zone radius of 0.8 mm. When m = 2 is selected, the step height becomes 6 μm. This can ensure maximum efficiency. On the other hand, if a different (for example, positive or negative) diffraction order should be used, the step height can be adjusted accordingly. For example, when m = 1 is selected, the first Fresnel zone radius can be 0.57 mm, and the step height can be 0.003 mm or 0.0033 mm. This exemplary embodiment represents a full diffractive design in which the diffraction grating is disposed on the back surface. There are also other embodiments with a diffraction grating limited to the central lens area (for example, 3 mm or 4 mm) that can enable improvements in mesopic and scotopic vision. This exemplary embodiment can be assembled using a material having a refractive index of 1.52 and an Abbe number of 42. Assume that the central lens thickness is, for example, 1 mm.

[0072] FIG. 8 presents a diffractive surface phase profile showing the phase map of a perfect diffractive surface (with 2π as the norm). On the other hand, in other exemplary embodiments, the diffractive grating can be limited, for example, to the central lens area (e.g., 3 mm or 4 mm, see FIG. 12B for example).

[0073] FIGS. 9A and 9B show the modulation transfer function (MTF) levels of an exemplary embodiment (the exemplary embodiment already described) where the longitudinal chromatic aberration in the model eye is a two-fold increase. Monochromatic (550 nm, FIG. 9A) and polychromatic (FIG. 9B) MTFs (solid lines) up to 100 lp / mm are shown. The dashed line (FIG. 9A) shows the minimum (monochromatic) MTF at 100 lp / mm that is acceptable for a single-focus IOL, and the dotted line refers to the diffraction-limited modulation transfer (MT).

[0074] The simulated optical quality in the model eye meets the requirements of the manufacturing standard (ISO 11979-2) for a single-focus lens, which requires that the monochromatic (550 nm) modulation transfer function (MTF) be 0.43 or more at 100 lp / mm. The exemplary embodiments described exceed this requirement with an MTF value of 0.58, which is near diffraction-limited performance (FIG. 9A). FIG. 9B shows the polychromatic MTF of the embodiment under consideration.

[0075] FIGS. 10A, 10B, and 10C show retinal image simulations obtained in the ISO 11979-2:2014 model eye with the exemplary embodiments described above (refer to FIGS. 4A / 4B and FIGS. 6A / 6B respectively), which are characterized by a two-fold or three-fold increase in LCA. Comparing the (spectrally weighted) monochromatic and polychromatic conditions, a significant increase in DoF was shown due to chromatic aberration. FIGS. 8A, 8B, and 8C present the retinal image simulations together with the corresponding defocus values. With a three-fold increase in LCA, equivalent image quality occurs over a 2D range (-1D to +1D). The intended myopic refractive correction target can expand the effective visual acuity range. Such an IOL can also provide a larger "landing zone", which enables better refractive outcomes to be achieved postoperatively.

[0076] Figure 11 shows the simulated logMAR visual acuity for three conditions in the defocus range from +1D to -2D. The vertical dashed line indicates the position of the best far focus.

[0077] The quantification of depth of focus extension is described below.

[0078] Natural, double, and triple LCA conditions can be compared by their image quality measurement methods with a 3mm pupil. For this, the area under the MTF (MTFa) can be obtained based on the following equation.

[0079]

Equation

[0080] Here, d determines the sampling of the spatial frequency (f). MTFa can be derived for each defocus position from +1D to -2D and converted to clinical visual acuity by the following model. VA = a·MTFa b +c

[0081] The coefficients used in the calculation can be obtained from ANSI Z80.35-2018 (a = 0.085, b = -1.0, and c = -0.21). In Figure 11, three conditions regarding the simulated visual acuity are compared. At the best far focus (0D), the double LCA increase causes only a 0.02 logMAR change in visual acuity, and the triple increase causes only a 0.05 logMAR change. Still, the predicted visual acuity levels are better than the mean of the normal population (i.e., 0.00 logMAR or 20 / 20 Snellen). The natural state LCA model demonstrated a significant deterioration of the optical quality under defocus compared to the IOL with increased LCA. For example, at 1.50D (67cm viewing distance), doubling the eye's LCA improved the visual acuity by only 0.07 logMAR, but tripling it resulted in 0.11 logMAR.

[0082] Figures 12A and 12B show further exemplary embodiments of an embeddable lens that includes a refractive element that causes chromatic aberration and an element that promotes an increase in chromatic aberration. Therein, the element that promotes an increase in chromatic aberration includes a diffraction structure. In particular, the diffraction structure is a Fresnel structure, particularly a kinoform lens structure. The diffraction structure includes a diffraction profile. In particular, the diffraction profile extends from a first Fresnel zone of the diffraction structure to an edge of the refractive element. The structures shown in FIGS. 12A and 12B can be used, for example, in combination with the exemplary embodiments described with respect to FIGS. 8, 9A, and 9B.

[0083] In one exemplary option shown in FIG. 12A, the design of the embeddable lens is, for example, completely diffractive, in which case the diffraction structure (Fresnel rings) extends to the edge of the lens. In another exemplary option shown in FIG. 12B, the design of the embeddable lens is, for example, partially diffractive, in which case the diffraction structure (Fresnel rings) extends to a diameter of 3 mm, 4 mm, or 4.5 mm, thereby improving scotopic / mesopic vision and promoting manufacturability. In FIGS. 12A and 12B, the kinoform lens structure is a negative kinoform lens structure, and this negative kinoform lens structure has a diffraction profile that extends from the center to either the edge of the lens (FIG. 12A) or a determined distance from the center (FIG. 12B). The kinoform lens structures in FIGS. 12A and 12B have a (continuous) "sawtooth" surface profile with a minimum at the center (at a radius of 0 mm, i.e., X = Y = 0 mm). The "sawtooth" maximum (represented as concentric solid lines) at which the profile reaches the step height decreases with the distance from the center.

[0084] The expression "A and / or B" is contemplated to include any one of the following three concepts: (i) A, (ii) B, (iii) A and B. Further, the article "a" should not be understood as "one". That is, the use of the expression "an element" does not exclude the existence of further elements. The term "comprising" should be understood in an unrestricted sense, i.e., in the sense that an object "comprising element A" can also include further elements in addition to element A. Further, the term "comprising" may be limited to "consisting of", i.e., limited to consisting only of the specified elements. The expression "A and / or B" can also be understood to mean "at least one of A or B", or "at least one of the following: A or B".

[0085] All embodiments presented are merely examples, and it is understood that any feature presented for a particular exemplary embodiment can be used in any manner, by itself, or in combination with any feature presented for the same or another particular exemplary embodiment, and / or in combination with any other feature not mentioned. In particular, it is to be understood that the exemplary embodiments presented herein are disclosed in all possible combinations with each other, as long as they are technically reasonable and as long as these exemplary embodiments are not alternatives to each other. It is further understood that any feature presented for an exemplary embodiment in a particular category (method / apparatus / computer program / system) can also be used in a corresponding manner in an exemplary embodiment in any other category. It should also be understood that the presence of a feature in an exemplary embodiment presented does not necessarily mean that this feature is essential and cannot be omitted or substituted.

[0086] A description that a certain feature includes at least one of the features subsequently recited is not essential in that the feature includes all of the features subsequently recited or includes at least one of the features of the plurality of features subsequently recited. Also, it is possible to select the recited features in any combination or to select only one of the recited features. A specific combination of all of the features subsequently recited can also be considered. Also, it can be made possible that there are a plurality of only one of the recited features.

[0087] The order of all of the method steps presented above is not essential and there may be alternative orders. Nevertheless, a specific order of method steps as placed in the syntax of the claims or in the above description shall be considered as one possible order of the method.

[0088] The subject matter has been described by way of example embodiments. It should be noted that there are alternative ways and modifications which are apparent to those skilled in the art and which can be carried out without departing from the scope of the appended claims.

Claims

1. An embeddable lens including a refractive element that causes chromatic aberration and an element that promotes an increase in the chromatic aberration, wherein the element that promotes the increase in the chromatic aberration includes a diffraction structure that is a negative diffraction structure and a kinoform lens structure.

2. The embeddable lens according to claim 1, wherein the increase in the chromatic aberration is an increase of at least two times, preferably at least three times, particularly between 3 and 7 times.

3. The embeddable lens according to claim 1 or 2, wherein the refractive element has a rear surface and a front surface, and the rear surface and / or the front surface has an aspherical or spherical shape.

4. The element that promotes the increase in the chromatic aberration increases the distance between the focal point of red light having a wavelength of 650 nm and the focal point of blue light having a wavelength of 450 nm to 5 to 13 mm under standard indoor conditions, and / or the element that promotes the increase in the chromatic aberration increases the distance between the focal points of red light of 656 nm and blue light of 486 nm to between 5 mm and 10 mm when measured in vitro or in an immersion having a refractive index of 1.333, and / or the element that promotes the increase in the chromatic aberration increases the distance between the focal points of red light of 656 nm and blue light of 486 nm to between 0.8 mm and 1.3 mm when measured in vivo or in the natural position, particularly the refractive element causes a chromatic aberration in which the distance between the focal points of red light and blue light is 1 to 2 mm when measured in vitro or in the immersion, and / or 0.4 to 0.6 mm when measured in vivo or in the natural position. The embeddable lens according to any one of claims 1 to 3.

5. The embeddable lens according to claim 4, wherein the refractive element has a rear surface and a front surface, and the diffraction structure is on the rear surface and / or the front surface.

6. The embeddable lens according to claim 4 or 5, wherein the diffraction structure has a power of at most -1 D, particularly the power is between -1 D and -11 D.

7. The embeddable lens according to any one of claims 4 to 6, wherein the diffraction structure includes a diffraction profile, particularly the diffraction profile extends from the first Fresnel zone of the diffraction structure to the edge of the refractive element, or the diffraction profile extends from the center of the refractive element to the edge of the refractive element.

8. Both the refractive element and the element that promotes the increase in chromatic aberration include a diffractive-refractive zone centered on the center of the refractive element. In particular, the diffractive-refractive zone has a diameter of 3 mm to 4.5 mm. The implantable lens according to any one of claims 1 to 7.

9. The implantable lens according to any one of claims 1 to 8, wherein the diffraction structure utilizes a first diffraction order and / or a second diffraction order.

10. The implantable lens according to any one of claims 1 to 9, wherein the refractive element has a nominal power range of -5D to 40D.

11. The implantable lens according to any one of claims 1 to 10, wherein the element that promotes the increase in chromatic aberration increases the chromatic aberration by at least 1D, preferably at least 2D, in the spectral range of 450 nm to 650 nm.

12. The implantable lens according to any one of claims 1 to 11, wherein the element that promotes the increase in chromatic aberration and the refractive element are made of the same material. In particular, the element that promotes the increase in chromatic aberration and the refractive element form an integral unit.

13. The kinoform lens structure includes, in particular, a serrated surface profile superimposed on the front and / or rear surface of the refractive element. The kinoform lens structure can optionally have a lower central zone for the first diffraction step. The implantable lens according to any one of claims 1 to 12.

14. The serrated surface profile has a minimum value at the center. In particular, the distance between the maximum values at which the serrated surface profile reaches the step height decreases with the distance from the center of the refractive element. The implantable lens according to claim 13.

15. A method for manufacturing an implantable lens according to any one of claims 1 to 14, including the step of etching and / or machining the element that promotes the increase in chromatic aberration on the front and / or rear surface of the refractive element.

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