Folded waveguide diffractive intraocular lens and method of designing the same

Abstract

The application provides a fold-diffraction coupling full-vision artificial lens and a design method thereof. A front optical surface of the artificial lens comprises a plurality of groups of diffraction rings arranged in a radial direction in sequence. Each group of diffraction rings comprises at least two diffraction rings with substantially equal curvature radii in a direction from the center of the front optical surface to the periphery, and at least one transition diffraction ring with a decreasing curvature radius following the at least two diffraction rings. The curvature radius of the transition diffraction ring is smaller than the average curvature radius of the diffraction rings with substantially equal curvature radii, and the difference increases with the increase of the basic curvature radius and decreases with the increase of the target intraocular power. The curvature radius of the transition diffraction ring at the outer edge is substantially equal to the curvature radius of the transition diffraction ring at the innermost edge. The artificial lens solves the defects of the existing pure diffraction multifocal artificial lens, such as the hard transition of far, intermediate and near vision, and the lack of continuous focal depth. The artificial lens also makes up for the defects of the pure refractive EDOF, such as the insufficient near focal power and the blurred vision at a short distance.

Description

Technical Field

[0001] This invention relates to the field of ophthalmic medical device technology, specifically to a refracting-diffraction coupled full-range intraocular lens and its design method. Background Technology

[0002] Cataracts and presbyopia are common eye diseases among middle-aged and elderly people. In clinical treatment, it is common to implant an artificial lens to replace the diseased or disabled natural lens in order to restore the refractive imaging function of the eye. As patients' requirements for postoperative visual quality continue to increase, traditional monofocal intraocular lenses with a single visual range are no longer sufficient to meet the visual needs of all scenarios in daily life, such as seeing distant objects, looking at screens at work, and reading at close range. Multifocal intraocular lenses have become the mainstream research and development direction in the industry.

[0003] Currently, intraocular lenses (IOLs) widely used in clinical practice are mainly divided into two categories: pure diffraction multifocal IOLs and pure refractive continuous depth of focus (EDOF) IOLs. Pure diffraction multifocal IOLs have multiple levels of diffraction rings of equal height and spacing on the anterior optical surface. Through the principle of diffraction, the incident light is dispersed to multiple focal points, achieving multifocal imaging at far, intermediate, and near distances. The diffraction rings of this type of lens are uniformly determined by classical diffraction formulas, and the focal position is fixed, providing clear multifocal vision. Pure refractive continuous depth of focus (EDOF) IOLs, on the other hand, use a single aspherical refractive structure. Through continuous changes in the curvature of the aspherical surface, the focal depth range is extended, allowing the focal point to continuously extend within a certain range, thus providing a smooth experience of distance transition.

[0004] The aforementioned existing technologies all have obvious technical defects. Pure diffractive multifocal intraocular lenses have discrete focal points, resulting in harsh transitions in vision at near, intermediate, and far distances, and a lack of continuous depth of focus. Pure refractive EDOF intraocular lenses use a single aspherical refractive structure, which has the advantages of continuous depth of focus and minimal optical interference, and can effectively improve the problem of visual tomography. However, they have insufficient refractive power for near focal points, resulting in blurred vision at near distances. They cannot achieve the ultra-clear near vision provided by standard multifocal intraocular lenses and cannot cover the full range of vision needs from far to near. Summary of the Invention

[0005] The purpose of this invention is to provide a refracto-diffraction coupled full-range intraocular lens and its design method. This refracto-diffraction coupled full-range intraocular lens can achieve clear imaging of the far, intermediate and near focal points, and ensure continuous and smooth depth of focus throughout the entire range.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The first aspect of the present invention provides a refractive-diffraction coupled full-range intraocular lens, comprising an optical body, the optical body including a front optical surface and a rear optical surface disposed opposite to each other, the front optical surface being aspherical and the rear optical surface being spherical, the optical body performing refractive-diffraction coordinated modulation on incident light to form a far-field focus, an intermediate-field focus, and a near-field focus, wherein the far-field focus is an additional optical power of 0D, the intermediate-field focus is an additional optical power of +1.5D, and the near-field focus is an additional optical power of +3.0D. The anterior optical surface includes multiple sets of diffraction rings arranged radially. Each set of diffraction rings includes at least two diffraction rings with substantially equal radii of curvature, and at least one transition diffraction ring with decreasing radii of curvature following it. The radii of curvature of the transition diffraction ring are smaller than the average radii of curvature of the diffraction rings with substantially equal radii of curvature. The difference is determined based on the target intraocular power of the intraocular lens and the basic radii of curvature of the anterior optical surface. The difference increases with the increase of the basic radii of curvature and decreases with the increase of the target intraocular power. Among the multiple transition diffraction rings arranged radially, the radii of curvature of the outermost transition diffraction ring are substantially equal to the radii of curvature of the innermost transition diffraction ring.

[0007] In one embodiment, the total number of diffraction rings on the front optical surface is 6 to 15, and the number of multiple sets of diffraction rings is 2 to 5.

[0008] In one embodiment, the number of transition diffraction rings with decreasing curvature radii in each group of diffraction rings is one, and the number of diffraction rings with substantially equal curvature radii in each group of diffraction rings is two.

[0009] In one embodiment, the number of diffraction rings is 10, arranged radially from the inside to the outside as the first diffraction ring to the tenth diffraction ring; The first diffraction ring and the second diffraction ring have basically the same radius of curvature. The third diffraction ring is a transition diffraction ring, and its radius of curvature is 2mm to 7mm smaller than that of the first and second diffraction rings. The curvature radii of the fourth and fifth diffraction rings are basically equal. The sixth diffraction ring is a transition diffraction ring, and its curvature radius is 2mm to 7mm smaller than that of the fourth and fifth diffraction rings. The curvature radii of the seventh diffraction ring are basically equal to those of the eighth and ninth diffraction rings. The tenth diffraction ring is a transition diffraction ring, and its curvature radius is 2 mm to 7 mm smaller than that of the seventh, eighth, and ninth diffraction rings. The radius of curvature of the tenth diffraction ring is approximately equal to that of the third diffraction ring.

[0010] In one embodiment, the outer boundary radii of the first to tenth diffraction rings are respectively: First diffraction ring: 0.73mm~0.80mm; Second diffraction ring: 1.05mm~1.10mm; Third diffraction ring: 1.47mm~1.50mm; Fourth diffraction ring: 1.65mm~1.70mm; Fifth diffraction ring: 1.85mm~1.90mm; Sixth diffraction ring: 2.07mm~2.10mm; Seventh diffraction ring: 2.19mm~2.25mm; Eighth diffraction ring: 2.32mm~2.41mm; Ninth diffraction ring: 2.45mm~2.55mm; Tenth diffraction ring: 3.0 mm.

[0011] In one embodiment, among the multiple diffraction rings of the front optical surface, the odd-numbered diffraction rings have diffraction steps at their ends, and the even-numbered diffraction rings are smoothly connected to the adjacent odd-numbered diffraction rings; the height of the diffraction steps is a uniform value.

[0012] In one embodiment, even-numbered diffraction rings are smoothly connected to adjacent odd-numbered diffraction rings to eliminate stray light caused by structural abrupt changes.

[0013] In one embodiment, the modulation transfer function difference between the far-field, mid-field, and near-field focal points at a spatial frequency of 50 lp / mm and a pupil diameter of 3 mm is ≤15%. Within the 0D to +3.0D defocus range, the modulation transfer function at a spatial frequency of 50 lp / mm is ≥0.2.

[0014] In one embodiment, the light energy distribution ratio of the far-field focus, the mid-field focus, and the near-field focus is 4:3:3.

[0015] In one embodiment, the diameter of the optical surface of the optical body is 5.5mm to 6.5mm; the radius of curvature of the rear optical surface is 15mm, 20mm or 25mm.

[0016] A second aspect of the present invention provides a method for designing a refracting-diffraction coupled full-range intraocular lens, used to design the intraocular lens as described above, characterized by comprising the following steps: The basic spherical radius of curvature of the optical surface is selected based on the material of the intraocular lens and the target intraocular optical power. The basic spherical radius of curvature of the anterior optical surface is determined based on the target intraocular optical power, the anterior optical surface optical power, the posterior optical surface optical power, the material refractive index, and the intraocular medium refractive index. With the goal of achieving a modulation transfer function ≥0.4 at a spatial frequency of 100 lp / mm under a pupil diameter of 3 mm and at the far focal point of 0D, and controlling the spherical aberration of the entire field of view within ±0.05 μm, the front optical surface is optimized using an even-order aspherical formula to obtain the basic aspherical front optical surface. Diffraction rings are added to the optical surface of the basic aspherical surface, wherein the initial boundary position and initial step height of each diffraction ring are calculated based on the focal length corresponding to the near-distance additional optical power. Each diffraction ring of the front optical surface is set as an independent aspherical surface. With the goal of the modulation transfer function difference at the three focal points of far focal point 0D, mid focal point +1.5D, and near focal point +3.0D being ≤15% and the modulation transfer function not lower than 0.2 in the defocus range of 0~+3.0D, the aspherical surface of each independent aspherical surface is optimized by using the even-order aspherical surface formula to obtain the final boundary position and radius of curvature of each diffraction ring.

[0017] In one embodiment, the even-order aspherical formula is as follows:

[0018] Where: r is the radial coordinate, R is the radius of curvature of the basic sphere, and k is the quadratic surface coefficient. Here are the coefficients of the higher-order terms of the aspherical surface, and n is a natural number not less than 1.

[0019] In one embodiment, the position of the diffraction rings of the diffraction structure is determined by the following formula: rm=

[0020] Where rm is the outer boundary radius of the m-th diffraction ring, m is the diffraction ring order, λ is the incident light wavelength, and f' is the lens focal length; The step height of the diffraction rings in the initial diffraction structure is determined by the following formula:

[0021] in, λ0 = 0.00055, where n1 is the refractive index of the intraocular lens material when immersed in the eye, n2 is the refractive index of the aqueous humor or vitreous medium in the eye.

[0022] In one embodiment, the following formula is used to determine the basic spherical radius of curvature of the anterior optical surface based on the target intraocular optical power, the anterior optical surface optical power, the posterior optical surface optical power, the material refractive index, and the intraocular medium refractive index: F = Ff + Fb (tc / n1) Ff Fb; where F is the overall intraocular optical power of the intraocular lens, Ff is the single-surface optical power of the anterior surface, Fb is the single-surface optical power of the posterior surface, tc is the central optical thickness of the intraocular lens, n1 is the refractive index of the intraocular lens material under intraocular immersion conditions, and n2 is the refractive index of the aqueous humor or vitreous medium; Ff=(n1 n2) / ra,Fb=( n2 n1) / rb, where ra is the radius of curvature of the base spherical surface of the front optical surface and rb is the radius of curvature of the base spherical surface of the rear optical surface.

[0023] The refractive-diffraction coupled full-range intraocular lens provided in this embodiment of the invention includes an optical body, which comprises a front optical surface and a rear optical surface arranged opposite to each other. The front optical surface is aspherical, and the rear optical surface is spherical. The optical body performs refractive-diffraction coordinated modulation on the incident light to form a far-field focal point, an intermediate-field focal point, and a near-field focal point. The far-field focal point is an additional optical power of 0D, the intermediate-field focal point is an additional optical power of +1.5D, and the near-field focal point is an additional optical power of +3.0D. The front optical surface includes multiple sets of diffraction rings arranged radially. Each set of diffraction rings includes at least two diffraction rings with substantially equal radii of curvature, and at least one transition diffraction ring with decreasing radii of curvature following it. The radius of curvature is smaller than the average radius of curvature of the diffraction rings that are substantially equal in radius of curvature. The difference is determined based on the target intraocular optical power of the intraocular lens and the basic radius of curvature of the anterior optical surface. This difference increases with the increase of the basic radius of curvature and decreases with the increase of the target intraocular optical power. Among the multiple transition diffraction rings arranged radially, the radius of curvature of the outermost transition diffraction ring is substantially equal to that of the innermost transition diffraction ring. This intraocular lens achieves a smooth accumulation of additional optical power from 0D to +3.0D, ensuring that the defocus curve is seamless between the three focal points and that intermediate vision does not collapse. This solves the defects of existing pure diffraction multifocal intraocular lenses, such as abrupt transitions between far, intermediate, and near vision and the lack of continuous focal depth. By segmenting and accumulating multiple sets of transition diffraction rings, +1.5D and +3.0D additional focal points are achieved, compensating for the insufficient near focal refractive power and blurred near vision of pure refractive EDOF lenses. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the anterior optical surface of the refracting-diffraction coupled full-range intraocular lens provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the fold-diffraction coupling type full-range intraocular lens provided in an embodiment of the present invention; Figure 3 A cross-sectional view of a fold-diffraction coupled full-range intraocular lens provided in an embodiment of the present invention; Figure 4 This is a defocus curve diagram of a refracting-diffraction coupled full-range intraocular lens provided in an embodiment of the present invention; Figure 5 This is a defocus curve diagram of an intraocular lens with extended focal depth in the existing technology. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] In the description of this invention, it should be understood that the terms “comprising” and “having” as used herein, and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0028] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. It should be understood that the term "and / or" as used herein is merely a description of the relationship between related objects, indicating that three relationships may exist; for example, A and / or B can represent: A alone, A and B simultaneously, and B alone. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0030] The following detailed description of the folding-diffraction coupling full-range intraocular lens and its design method provided by the present invention, with reference to specific embodiments, is provided in detail.

[0031] Figure 1 This is a schematic diagram of the anterior optical surface of the refractive-diffraction coupled full-range intraocular lens provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of the structure of the folding-diffraction coupling type full-range intraocular lens provided in an embodiment of the present invention. Figure 3 This is a cross-sectional view of a fold-diffraction coupled full-range intraocular lens provided in an embodiment of the present invention. Figure 4 For the defocus curve diagram of the refracting-diffraction coupling full-range intraocular lens provided in the embodiments of the present invention, please refer to... Figure 1-4 The first aspect of this invention provides a refractive-diffraction coupled full-range intraocular lens, comprising an optical body 1, the optical body 1 including a front optical surface 11 and a rear optical surface 12 disposed opposite to each other, the front optical surface 11 being aspherical and the rear optical surface 12 being spherical, the optical body 1 performing refractive-diffraction coordinated modulation on incident light to form a far-field focus, an intermediate-field focus and a near-field focus, wherein the far-field focus is an additional optical power of 0D, the intermediate-field focus is an additional optical power of +1.5D, and the near-field focus is an additional optical power of +3.0D. The front optical surface 11 includes multiple sets of diffraction rings arranged radially. Each set of diffraction rings, extending outward from the center of the front optical surface 11, includes at least two diffraction rings with substantially equal radii of curvature, followed by at least one transition diffraction ring with decreasing radii of curvature. The radii of curvature of the transition diffraction rings are smaller than the average radii of curvature of the diffraction rings with substantially equal radii of curvature. The difference is determined based on the target intraocular optical power of the intraocular lens and the basic radii of curvature of the front optical surface. This difference increases with increasing basic radii of curvature and decreases with increasing target intraocular optical power. Among the radially arranged transition diffraction rings, the radii of curvature of the outermost transition diffraction ring are substantially equal to those of the innermost transition diffraction ring. In this embodiment, refractive-diffraction co-modulation refers to the aspherical refractive substrate of the front optical surface and the diffraction ring structure jointly distributing optical power and modulating the phase of the incident light to achieve multifocal imaging.

[0032] The optical body 1 in this embodiment is made of a foldable hydrophobic or hydrophilic acrylic material and is used to replace the diseased natural lens after implantation in the eye. The diffraction ring diameter of the optical body 1 is set to 5.5 mm to 6.5 mm, preferably 6.0 mm, to adapt to the imaging needs of different human eye pupil diameters.

[0033] like Figure 2 As shown, the posterior optical surface 12 in this embodiment is spherical. A sphere is the most basic and easily processed surface shape in optical fabrication, reducing processing difficulty, increasing yield, and ensuring the stability of the basic refractive power. The radius of curvature of the posterior optical surface 12 is not a fixed value, but is selected based on the target optical power of the intraocular lens and the refractive index of the material used. Specifically, different patients require different base powers of lenses to replace the removed natural lens due to differences in axial length—the commonly used intraocular lens power range is approximately -10D to 36D, covering the actual needs of over 95% of patients. Furthermore, different intraocular lens materials (such as hydrophobic acrylates, hydrophilic acrylates, etc.) have different refractive indices (usually between 1.50 and 1.58), resulting in different optical powers for the same radius of curvature under different refractive index materials. In the design method of the present invention, based on the above two factors, a suitable radius of curvature of the rear optical surface can be selected from the range of 10mm to 100mm. Among them, 15mm, 20mm, and 25mm are mature and preferred values ​​that have been clinically verified over a long period of time, corresponding to different optical power ranges and material combinations. Those skilled in the art can select other radii of curvature according to actual needs.

[0034] In this embodiment, the posterior optical surface 12 provides the intraocular lens with a basic far-field refractive power (i.e., the basic optical power corresponding to the 0D far-field focal length). For example, for a 20D intraocular lens, the 20D basic optical power is mainly determined by the curvature of the posterior optical surface 12 and the basic curvature of the anterior optical surface 11. The far-field focal length (0D) corresponds to this basic optical power, enabling the patient to see objects at infinity (such as road signs, television screens, etc.). The intermediate-field focal length (+1.5D) and near-field focal length (+3.0D) are additional optical powers provided by the diffraction structure of the anterior optical surface 11 on top of this basic optical power. +1.5D corresponds to a viewing distance of approximately 67cm (computer office distance), and +3.0D corresponds to a viewing distance of approximately 33cm (mobile phone reading distance). Both are calculated from the corresponding focal length using the formula D=1 / f.

[0035] In this embodiment, the front optical surface 11 is an aspherical surface. A diffraction ring structure is superimposed on the basic aspherical substrate to form a mixed refractive and diffractive surface shape. The basic surface shape of the front optical surface 11 is an even-order aspherical surface, and its surface shape is given by the following aspherical formula. Determined. Where r is the radial coordinate (i.e., the perpendicular distance from the optical axis), R is the radius of curvature of the basic sphere, k is the quadratic surface coefficient, and a... n Here are the coefficients of higher-order terms in aspherical surfaces (n is a natural number not less than 1, usually taken as a4, a6, a8, etc.). In this formula, when k=0 and all a... n When =0, Z(r) is spherical; therefore, the aspherical surface is the result of optimization based on the spherical surface by introducing quadratic surface coefficients and higher-order coefficients. In this embodiment, the basic aspherical surface provides part of the basic far-field refractive power (sharing the optical power of the 0D far focal point with the rear optical surface 12), and through the optimization of the aspherical coefficients, corrects the spherical aberration of the human eye, improving the quality of far-field imaging. In this embodiment, with the goal of achieving a modulation transfer function ≥0.4 at the 0D far focal point with a pupil diameter of 3mm and a spatial frequency of 100lp / mm, and controlling the spherical aberration across the entire field of view within ±0.05μm, coefficients such as k, a4, a6, and a8 are optimized to obtain the front optical surface 11 of the basic aspherical surface. Multiple diffraction rings are radially superimposed on the aforementioned basic aspherical surface substrate on the front optical surface 11. These diffraction rings are formed by processing a series of concentric annular step structures on the front optical surface 11, as shown in the attached figure. Figure 3 The cross-sectional view is shown. Along the center of the anterior optical surface 11 outwards, each set of diffraction rings includes at least two diffraction rings with substantially equal radii of curvature, and at least one transition diffraction ring with decreasing radii of curvature following it. Traditional pure diffraction multifocal intraocular lenses employ diffraction rings of equal height and spacing, the positions of which are determined by the diffraction formula rm =

[0036] The only certainty is that all diffraction rings share the same set of curvature parameters, making it impossible to independently control the optical power contribution of different diffraction rings. This results in discrete depths of focus and breaks between focal points (see...). Figure 5 (As shown). In this embodiment of the invention, the diffraction rings of the front optical surface 11 are divided into multiple groups. Each group is periodically set with two diffraction rings with similar curvatures and a transition diffraction ring with decreasing curvature. Each diffraction ring has an independent radius of curvature R, quadratic surface coefficient k, and aspherical higher-order coefficients a4, a6, ... During the optimization process, the contribution of each diffraction ring to the three focal points is controlled to achieve a smooth energy transition from far to near distance.

[0037] The optical power of the diffraction rings with essentially equal radii of curvature in this application is: Fc = (n1-n2) / Rc, where Fc is the optical power of the diffraction rings with essentially equal radii of curvature, n1 is the refractive index of the intraocular lens material under intraocular immersion, n2 is the refractive index of the aqueous humor or vitreous humor, and Rc is the radius of curvature of the diffraction rings with essentially equal radii of curvature. Ft = (n1-n2) / Rt, where Ft is the optical power of the transition diffraction ring, n1 is the refractive index of the intraocular lens material under intraocular immersion, n2 is the refractive index of the aqueous humor or vitreous humor, and Rt is the radius of curvature of the transition diffraction ring. The additional optical power F_add = Ft - Fc = (n1-n2) (1 / Rt - 1 / Rc), from which we can derive Rc - Rt = F_add·Rc·Rt / (n1-n2). For a given additional optical power F_add, the difference in the radius of curvature Rc-Rt between the transition diffraction ring and the basic diffraction ring is determined by the optical power formula: Rc-Rt = F_add · Rt · Rc / (n1-n2), where Rt is the radius of curvature of the transition diffraction ring, and Rc is the radius of curvature of the diffraction ring (basic diffraction ring) with approximately equal radii of curvature. Under the condition that the refractive index of the material is determined, Rc-Rt is positively correlated with the radius of curvature of the basic diffraction ring: for low-optical-power crystals, the basic diffraction ring Rc is larger, and Rc-Rt increases accordingly; for high-optical-power crystals, the basic diffraction ring Rc is smaller, and Rc-Rt decreases accordingly. Those skilled in the art can determine the corresponding Rc-Rt value for different target intraocular optical powers based on the above formula. In the above formula, F_add takes the maximum design additional optical power (+3.0D) and is used to estimate the magnitude of the difference in curvature radius between the transition diffraction ring and the basic diffraction ring. In actual design, the curvature radius of each transition diffraction ring is determined by the multi-objective optimization in S105 below. In this embodiment, the curvature radius of the transition diffraction ring is smaller than the average curvature radius of the basic diffraction ring. The difference is determined based on the target intraocular optical power and the basic curvature radius of the anterior optical surface of the intraocular lens. The difference increases with the increase of the basic curvature radius and decreases with the increase of the target intraocular optical power. The higher the target intraocular optical power, the smaller the basic curvature radius of the anterior optical surface required to achieve that optical power, the smaller the curvature radius of the basic diffraction ring, and the smaller the difference in curvature radius between the transition diffraction ring and the basic diffraction ring. Therefore, the difference decreases with the increase of the target intraocular optical power. In this embodiment, the radius of curvature of the transition diffraction ring is smaller than the average radius of curvature of diffraction rings with essentially equal radii of curvature, used to generate additional optical power at mid-range (+1.5D) and near-range (+3.0D). For crystals of different optical power ranges from -10D to 36D, the 10D low-optical-power crystal has a larger basic radius of curvature, with the difference biased towards 5-7mm; the 30D high-optical-power crystal has a smaller basic radius of curvature, with the difference biased towards 2-4mm; and the 20D mid-optical-power crystal covers the entire range of 2-7mm.In this embodiment, the two radii of curvature being essentially equal means that the difference between the two radii of curvature is no more than 0.5 mm, where the radius of curvature of the diffraction ring refers to the average radius of curvature of the diffraction ring.

[0038] In this embodiment, among the multiple transition diffraction rings arranged radially, the radius of curvature of the outermost transition diffraction ring is approximately equal to that of the innermost transition diffraction ring, and the three transition diffraction rings contribute equally to the light energy of the mid / near focal point. The innermost transition diffraction ring (e.g. Figure 1 The middle A3 (with a radius of curvature of approximately 15 mm) is the first diffraction ring to introduce additional optical power at mid-range distances. The outermost transition diffraction ring (such as...) Figure 1 A10 (with a curvature radius of approximately 15mm) is the last diffraction ring that accumulates near-field additional optical power. The curvature radii of the two rings are basically equal. From the first transition diffraction ring to the last transition diffraction ring, the curvature values ​​are consistent, which limits the curvature variation of the front optical surface 11 to a controllable range, avoids abrupt changes in surface shape, and reduces stray light.

[0039] The working process of the refractive-diffraction coupled intraocular lens of the present invention is as follows: Parallel incident light first reaches the anterior optical surface 11. The aspherical substrate of the anterior optical surface 11 bears part of the basic refractive power, guiding most of the light rays to the far focal point (OD). At the same time, the aspherical coefficient corrects spherical aberration, improving the quality of far-field imaging. Simultaneously, multiple sets of diffraction rings on the anterior optical surface 11 apply phase modulation to the incident light: diffraction rings with similar curvature (such as...) Figure 1 The A1 / A2, A4 / A5, A7 / A8 / A9 rings are primarily responsible for maintaining the fundamental refractive power at a distance; the transition diffraction rings (such as...) Figure 1 By reducing the local radius of curvature (A3, A6, A10), additional optical power of +1.5D and +3.0D is accumulated in segments. Light rays from different diffraction rings undergo constructive interference at three positions: far (0D), medium (+1.5D), and near (+3.0D), forming three stable focal points. Because multiple transitional diffraction rings accumulate additional optical power radially, there are no energy holes in the defocus range between the three focal points, achieving continuous depth of focus coverage from 0D to +3.0D. Finally, the light rays exit through the rear optical surface 12 (spherical surface), which provides the remaining fundamental refractive power, ultimately converging the light rays onto the retina for imaging.

[0040] Figure 4 shows the defocus modulation transfer function (MTF) curve of the defocused intraocular lens with full-range focal depth extension according to the embodiment of the present invention. Figure 5 shows the defocused MTF curve of the focal depth extension intraocular lens in the comparative scheme. Figure 4 shows the 0~+4D defocus modulation transfer function (MTF) curve (50lp / mm) of the 20D intraocular lens of the embodiment of the present invention, calculated by ray tracing under the conditions of a 3mm standard human eye model pupil diameter, a center wavelength of 546nm, and simulating an aqueous humor refractive index of 1.336 and a lens refractive index of 1.5545. Figure 5 shows the defocus modulation transfer function (MTF) curve of the conventional pure refractive EDOF intraocular lens under the same test conditions. As can be seen from the comparison, the curve in Figure 4 simultaneously forms three clearly distinguishable effective imaging peaks at 20D, 21.5D, and 23D, corresponding to the focal points of far, intermediate, and near objects, respectively. The MTF values ​​of all three peaks remain at a high level, with a relatively moderate peak-to-valley difference, enabling continuous and stable imaging across the entire visual range. In contrast, the sample in Figure 5 only has the highest main peak near 20D, and the secondary peak corresponding to the intermediate focal point at 21.5D is significantly lower in height than the peak near 20D. The optical performance at the near focal point is further degraded, resulting in a narrower effective usable visual range. Therefore, the intraocular lens of this embodiment can evenly improve the imaging modulation transfer function at multiple distances (far, intermediate, and near), widening the effective continuous depth of focus range. Compared to conventional depth-of-focus intraocular lenses, it provides more balanced visual quality at intermediate and near distances, better meeting the needs of human vision across the entire range.

[0041] The anterior optical surface 11 of the refracting-diffraction coupled full-range intraocular lens in this embodiment includes multiple sets of diffraction rings arranged radially. Each set of diffraction rings includes at least two diffraction rings with substantially equal radii of curvature, and at least one transition diffraction ring with decreasing radii of curvature following it. The radii of curvature of the transition diffraction ring are smaller than the average radii of curvature of the diffraction rings with substantially equal radii of curvature. The difference is determined based on the target intraocular optical power of the intraocular lens and the basic radii of curvature of the anterior optical surface. The difference increases with the increase of the basic radii of curvature. The increase in power decreases as the intraocular optical power increases. Among the multiple transition diffraction rings arranged radially, the radius of curvature of the outermost transition diffraction ring is approximately equal to that of the innermost transition diffraction ring. This intraocular lens achieves a smooth accumulation of additional optical power from 0D to +3.0D through the paired near-single-ring transition structure of multiple sets of diffraction rings. This ensures that the defocus curve is seamless between the three focal points, without any collapse in intermediate vision, thus solving the defects of existing pure diffraction multifocal intraocular lenses, such as abrupt transitions in far, intermediate, and near vision and the lack of continuous focal depth. The segmented accumulation of multiple sets of transition diffraction rings achieves +1.5D and +3.0D additional focal points, compensating for the insufficient near focal refractive power and blurred near vision of pure refractive EDOF lenses.

[0042] Furthermore, the total number of diffraction rings on the front optical surface 11 is 6 to 15, and the number of multiple sets of diffraction rings is 2 to 5. Specifically, fewer than 10 diffraction rings (6 to 9) are suitable for crystals with a small optical area diameter (e.g., 5.5 mm) or low near-field additional optical power (e.g., +2.5D). Reducing the number of diffraction rings can reduce the difficulty of ultra-precision processing, while still achieving continuous depth of focus, with only a slight reduction in the near-field coverage area. More than 10 diffraction rings (11 to 15) are suitable for crystals with a large optical area (6.5 mm) or high-end depth-of-field optimized features. Increasing the number of diffraction rings can further improve the smoothness of the defocus curve, reduce the transition depression between focal points, and significantly improve the mid-range visual experience.

[0043] Optionally, each group of diffraction rings contains one transition diffraction ring with a decreasing radius of curvature, and two diffraction rings with substantially equal radii of curvature. In this embodiment, two diffraction rings with similar curvatures plus one diffraction ring with decreasing curvature appear repeatedly along the radial direction, forming a periodic gradual change in the radius of curvature along the radial direction. The additional optical power in this embodiment is not introduced all at once, but is accumulated in segments through multiple transition diffraction rings, achieving a smooth transition from 0D to +3.0D, avoiding abrupt changes in surface shape and stray light caused by excessive curvature changes in a single diffraction ring.

[0044] In one specific embodiment, the number of diffraction rings is 10, arranged radially from the inside out as the first diffraction ring A1 to the tenth diffraction ring A10; the first diffraction ring A1 and the second diffraction ring A2 have approximately the same radius of curvature; the third diffraction ring A3 is a transition diffraction ring, and its radius of curvature is 2mm to 7mm smaller than that of the first diffraction ring A1 and the second diffraction ring A2; the fourth diffraction ring A4 and the fifth diffraction ring A5 have approximately the same radius of curvature; the sixth diffraction ring A6 is a transition diffraction ring, and the tenth diffraction ring A10... The radius of curvature of the sixth diffraction ring A6 is 2mm to 7mm smaller than that of the fourth diffraction ring A4 and the fifth diffraction ring A5; the radius of curvature of the seventh diffraction ring A7 is approximately equal to that of the eighth diffraction ring A8 and the ninth diffraction ring A9; the tenth diffraction ring A10 is a transition diffraction ring, and its radius of curvature is 2mm to 7mm smaller than that of the seventh diffraction ring A7, the eighth diffraction ring A8, and the ninth diffraction ring A9; the radius of curvature of the tenth diffraction ring A10 is approximately equal to that of the third diffraction ring A3. In this embodiment, the 10 diffraction rings are divided into three groups. The first group (A1-A2-A3): A1 and A2 have similar curvatures (approximately 18mm, corresponding to the telephoto base); A3 is the first transition diffraction ring (curvature approximately 15mm, 2mm to 7mm smaller than A1 / A2), initially introducing approximately +1.0D to +1.5D of additional optical power at mid-range distance. The second group (A4-A5-A6): A4 and A5 return to the basic curvature of the telephoto lens, supplementing the telephoto light energy. A6 is the second transition diffraction ring, continuing to accumulate additional optical power to approximately +2.0D~+2.5D. The third group (A7-A8-A9-A10): The curvature of A7 is close to that of A1 (the basic telephoto lens). The curvatures of A8 and A9 begin to deflect towards the transition direction. A10 is the third transition diffraction ring with a curvature approximately equal to that of A3, ultimately accumulating to +3.0D of additional optical power at close range.

[0045] In this embodiment, the curvatures of the three transition diffraction rings (A3, A6, A10) are basically the same (all around 15mm), ensuring a uniform distribution of light energy at the three focal points (approximately 4:3:3). The equal curvatures of A10 and A3 form a closed loop, eliminating the abrupt change in focal depth of the outermost diffraction ring and ensuring a smooth transition throughout the 0 to +3.0D range.

[0046] Further, the outer boundary radii of the first diffraction ring A1 to the tenth diffraction ring A10 are as follows: First diffraction ring A1: 0.73mm~0.80mm; Second diffraction ring A2: 1.05mm~1.10mm; Third diffraction ring A3: 1.47mm~1.50mm; Fourth diffraction ring A4: 1.65mm~1.70mm; Fifth diffraction ring A5: 1.85mm~1.90mm; Sixth diffraction ring A6: 2.07mm~2.10mm; Seventh diffraction ring A7: 2.19mm~2.25mm; Eighth diffraction ring A8: 2.32mm~2.41mm; Ninth diffraction ring A9: 2.45mm~2.55mm; Tenth diffraction ring A10: 3.0mm. The above radius values ​​in this embodiment correspond to the specific dimensions under a 20D crystal and a +3.0D additional optical power design. The diffraction ring radii of crystals with different optical powers (-10D~36D) are obtained according to the diffraction ring radius calculation formula. The size range is the preferred value verified by actual processing and can cover most clinical needs.

[0047] In the plurality of diffraction rings of the front optical surface 11, the odd-numbered diffraction rings have diffraction steps at their ends, and the even-numbered diffraction rings are smoothly connected to the adjacent odd-numbered diffraction rings; the height of the diffraction steps is a uniform value. Exemplarily, in this embodiment, the odd-numbered diffraction rings (such as A1, A3, A5…) have a step of fixed height at their ends (i.e., the cross-section suddenly dips downwards), while the even-numbered diffraction rings (such as A2, A4…) do not have steps at their ends, directly and smoothly transitioning to the starting point of the next odd-numbered diffraction ring. The structure of the odd-numbered diffraction rings with their downward-dipping steps and the even-numbered diffraction rings with their smooth connection in this embodiment forms a sawtooth-shaped blazed grating structure in the cross-section. Within each diffraction cycle of this embodiment (one odd-numbered diffraction ring + one even-numbered diffraction ring), the curved surface slowly rises (even-numbered diffraction rings) and then suddenly drops (steps at the ends of the odd-numbered diffraction rings). This sawtooth shape can concentrate the incident light energy to specific diffraction orders—in this invention, the far-field focus and the near-field focus. This blazed grating, with its sawtooth profile, effectively concentrates light energy to the target order, significantly improving light energy utilization. The uniformity of the step height ensures consistent phase jumps in each diffraction cycle, allowing the contributions of different diffraction rings to the near-focus to be superimposed in phase, thus enhancing the concentration effect. If the step heights are different, the phase jumps in each cycle will be inconsistent, causing the diffracted light at the near-focus to cancel each other out, weakening the focusing effect.

[0048] In this embodiment, the even-numbered diffraction rings are smoothly connected to the adjacent odd-numbered diffraction rings, eliminating the multiple abrupt changes in surface shape caused by the step in each diffraction ring in the traditional equal-height step design, reducing stray light and diffraction artifacts at the step edges, as well as optical interference such as glare and starbursts.

[0049] In this embodiment, the far focal point is the 0D base refractive power focal point, the intermediate focal point is the +1.5D additional optical power focal point, and the near focal point is the +3.0D additional optical power focal point. The modulation transfer function (MTF) difference between the far, intermediate, and near focal points at a spatial frequency of 50 lp / mm with a pupil diameter of 3 mm is ≤15%; within the defocus range of 0D to +3.0D, the MTF at a spatial frequency of 50 lp / mm is ≥0.2. MTF is a core indicator for measuring the sharpness of an imaging system, ranging from 0 to 1, with higher values ​​indicating greater clarity. A spatial frequency of 50 lp / mm corresponds to medium detail in everyday life (such as faces and computer text); a spatial frequency of 100 lp / mm corresponds to high-precision detail (such as small print in a book). An MTF difference of ≤15% among the three focal points ensures uniform sharpness across the far, intermediate, and near focal points, preventing patients from experiencing a jump in clarity when looking at distant objects, computers, or mobile phones. Within the 0~+3.0D out-of-focus range, MTF≥0.2 ensures that there is no sharpness collapse at any intermediate distance from 0D to +3.0D (such as looking at a desktop computer screen, looking at a menu, etc.), and the depth of focus is continuous.

[0050] The light energy distribution ratio of the far-field, intermediate-field, and near-field focal points is 4:3:3. 40% of the incident light energy is allocated to the far-field focal point (to meet the needs of daytime long-distance eye use), 30% to the intermediate-field focal point (to meet the brightness needs of computer office work), and 30% to the near-field focal point (to meet the brightness needs of mobile phone reading).

[0051] Preferably, the diameter of the optical surface of the optical body 1 is 5.5mm to 6.5mm. This range covers the needs of patients with different pupil sizes in clinical practice. The larger the diameter of the optical surface, the better the imaging quality of large pupils in low-light environments. The radius of curvature of the rear optical surface 12 is 15mm, 20mm, or 25mm, which are standard empirical values ​​derived from the commonly used intraocular lens power range (-10D to 36D) and the refractive index of commonly used materials (1.50 to 1.58), respectively corresponding to low, medium, and high power requirements.

[0052] A second aspect of this invention provides a method for designing a refracto-diffraction coupled full-range intraocular lens (IOL), used to design the IOL as described in the above embodiments, comprising the following steps: S101. The basic spherical radius of curvature of the optical surface is selected based on the material of the intraocular lens and the target intraocular optical power. Specifically, the higher the refractive index of the material, the larger the radius of curvature required for the same optical power. In practical design, based on the refractive index of commonly used materials (1.50~1.58) and the optical power range (-10D~36D), the basic spherical radius of curvature of the rear optical surface is selected as three standard radii of curvature: 15mm, 20mm, and 25mm, as preferred engineering values. For example, if the intraocular lens is made of hydrophobic acrylate with a refractive index of 1.5545, the target intraocular power is 20D, and the radius of curvature of the rear optical surface is 25mm.

[0053] S102. Determine the basic spherical radius of curvature of the anterior optical surface based on the target intraocular optical power, the anterior optical surface optical power, the posterior optical surface optical power, the material refractive index, and the intraocular medium refractive index. Specifically, based on the target intraocular optical power, the optical power of the anterior optical surface, the optical power of the posterior optical surface, the refractive index of the material, and the refractive index of the intraocular medium, the basic spherical radius of curvature of the anterior optical surface is determined using the thick lens formula. The thick lens formula is: F = Ff + Fb - (tc / n1)×Ff×Fb, where F is the overall intraocular optical power of the intraocular lens, Ff is the single-surface optical power of the anterior surface (Ff=(n1-n2) / ra), Fb is the single-surface optical power of the posterior surface (Fb=(n2-n1) / rb), tc is the central optical thickness of the intraocular lens, n1 is the refractive index of the intraocular lens material under intraocular immersion conditions, n2 is the refractive index of the aqueous humor or vitreous medium, ra is the basic spherical radius of curvature of the anterior optical surface, and rb is the basic spherical radius of curvature of the posterior optical surface. For example, tc is 0.6mm, n1=1.5545, n2=1.336; F is 20D, rb is 25mm, and substituting into the above formula, we can get ra is 19.34mm.

[0054] S103. With the goal of achieving a modulation transfer function ≥0.4 at the far focal point of 0D and a spatial frequency of 100lp / mm under a pupil diameter of 3mm, and controlling the spherical aberration of the entire field of view within ±0.05μm, the basic front optical surface is optimized using an even-order aspherical formula to obtain the basic aspherical front optical surface. Specifically, the basic aspherical surface shape of the front optical surface adopts an even-order aspherical formula. Where r is the radial coordinate, R is the radius of curvature of the base sphere (here, the radius of curvature of the base sphere of the front optical surface), and k is the quadratic surface coefficient. Here, represents the higher-order aspherical coefficients, where n is a natural number not less than 1. This is the most commonly used aspherical expression in optical design, with intuitive parameters and high optimization efficiency. k is a quadratic surface coefficient used to control the conic section type of the surface shape; a4, a6, and a8 are higher-order aspherical coefficients used to correct spherical aberration and higher-order aberrations. The goal is to achieve a modulation transfer function ≥0.4 at a 3mm pupil diameter, at the 0D far focal point, and at a spatial frequency of 100lp / mm, while keeping the spherical aberration within ±0.05μm across the entire field of view. Optimizing the aspherical quadratic surface coefficients k and the higher-order aspherical coefficients yields the basic aspherical front optical surface. For example, after this optimization step, ra is adjusted to approximately 18mm.

[0055] S104. Add diffraction rings to the optical surface of the basic aspherical surface, wherein the initial boundary position and step height of each diffraction ring are obtained based on the focal length corresponding to the near-distance additional optical power. Specifically, on the optical surface in front of the basic aspherical surface, based on the focal length corresponding to the near-range additional optical power (+3.0D), the formula rm = is used to calculate the diffraction ring radius. Calculate the initial boundary positions of each diffraction ring. For example, the focal length corresponding to a +3.0D near-range additional optical power is (f' = 1 / 3 ≈ 0.333m = 333mm). Substitute these values ​​into the diffraction formula (rm = ...). The initial radius of each diffraction ring can then be calculated. The near-field additional optical power corresponds to a focal length of 33cm viewing distance. The initial period of the diffraction ring is calculated based on this maximum additional optical power to ensure the widest coverage of the near-focus area. After selecting the phase depth Δφ according to the trifocal light energy distribution requirements, the step height is directly calculated using the formula h=λ0Δφ / (2π(n1-n2)). For example, in this embodiment, the step height is calculated using the formula rm= Substituting λ=550nm and f'=333mm, the outer boundary radii of the diffraction rings are obtained as r1=0.606, r2=0.856, r3=1.049, ..., r17≈2.5mm (the initial calculation range boundary of the diffraction rings). r1 corresponds to the outer boundary radius of the first diffraction ring, r2 to the outer boundary radius of the second diffraction ring, ..., r17 to the outer boundary radius of the seventeenth diffraction ring. In this embodiment, the light energy distribution ratio of the three focal points is optimized within the phase depth range of π~2π according to the requirement of approximately 4:3:3. The step height is calculated using the basic diffraction phase formula h=λ0Δφ / (2π(n1-n2)). Let n1 be the phase difference caused by the diffraction rings on the incident light, n2 be the refractive index of the intraocular lens material when immersed in the eye, and λ0 be 0.00055. Both λ and λ0 refer to the incident light wavelength (550 nm). In this embodiment, the odd-numbered diffraction rings have diffraction steps at their ends, and the even-numbered diffraction rings are smoothly connected to adjacent odd-numbered diffraction rings. The height of the diffraction steps is a uniform value; for example, the height of the diffraction steps is on the order of 0.001 mm.

[0056] S105. Each diffraction ring of the front optical surface is set as an independent aspherical surface. With the goal of the modulation transfer function difference at the three focal points of far focal point 0D, mid focal point +1.5D, and near focal point +3.0D being ≤15% and the modulation transfer function not lower than 0.2 in the defocus range of 0~+3.0D, the aspherical surface of each independent aspherical surface is optimized using the even-order aspherical surface formula to obtain the final boundary position and radius of curvature of each diffraction ring.

[0057] Specifically, based on the target additional optical power corresponding to the radial position of each diffraction ring, the initial value of the radius of curvature of each diffraction ring is calculated using the optical power formula Ff=(n1- n2) / R. Then, the radius of curvature, k, higher-order coefficients, and diffraction ring boundaries of all diffraction rings are used as optimization variables. The optimization objective is to ensure that the difference in modulation transfer function at the three focal points (0D at the far focal point, +1.5D at the mid focal point, and +3.0D at the near focal point) is ≤15%, and the modulation transfer function within the defocus range of 0~+3.0D is not lower than 0.2. Iterative optimization is performed using ZEMAX optical design software. For example, the target additional optical power of the 17 initial diffraction rings obtained in S104 increases linearly from 0D to +3.0D from the center to the edge. That is, the target additional optical power of the j-th diffraction ring is: P_add(j) = (j 1) / (N 1) × 3.0D, where N=17 (total number of initial diffraction rings), for example: P_add (1) (innermost diffraction ring) ≈ 0D, P_add (2) ≈ 0.18D, P_add (3) ≈ 0.37D…… P_add (9) ≈ 1.50D (corresponding to the midpoint)…… P_add (17) (outermost diffraction ring) ≈ 3.0D. During the optimization convergence process, the difference in the radius of curvature of some adjacent diffraction rings is less than the preset threshold (0.1~0.5mm). Under the premise of meeting the optimization objective, such rings are merged into one diffraction ring; after optimization convergence, the initial 17 rings are finally merged into 10 rings. The optimized outer boundary radii of the diffraction rings are A1=0.765mm, A2=1.075mm, A3=1.485mm, A4=1.675mm, A5=1.875mm, A6=2.085mm, A7=2.220mm, A8=2.365mm, A9=2.500mm, and A10=3.000mm. The radii of curvature of A1 and A2 are close to 18mm. The radius of curvature of A3 is 3mm smaller than that of A1 and A2, and is approximately 15mm. The radii of curvature of A4 and A5 are close to that of A1, and are approximately 18mm. The radius of curvature of A6 is 3mm smaller than that of A4 and A5, and is approximately 15mm. The radius of curvature of A10 is 3mm smaller than that of A7, A8, and A9. The radii of curvature of A7, A8, and A9 are close to that of A3, and are approximately 15mm. In the above example, A1 represents the first diffraction ring, A2 represents the second diffraction ring, ..., A10 represents the tenth diffraction ring.

[0058] In the above description, the terms "an embodiment," "some embodiments," "example," "specific example," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0059] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A refractive-diffraction coupled full-range intraocular lens, characterized in that: The system includes an optical body comprising a front optical surface and a rear optical surface arranged opposite to each other. The front optical surface is aspherical, and the rear optical surface is spherical. The optical body performs refraction-diffraction co-modulation on incident light to form a far-distance focal point, a mid-distance focal point, and a near-distance focal point. The far-distance focal point is an additional optical power of 0D, the mid-distance focal point is an additional optical power of +1.5D, and the near-distance focal point is an additional optical power of +3.0D. The anterior optical surface includes multiple sets of diffraction rings arranged radially. Each set of diffraction rings includes at least two diffraction rings with substantially equal radii of curvature, and at least one transition diffraction ring with decreasing radii of curvature following it. The radii of curvature of the transition diffraction ring are smaller than the average radii of curvature of the diffraction rings with substantially equal radii of curvature. The difference is determined based on the target intraocular power of the intraocular lens and the basic radii of curvature of the anterior optical surface. The difference increases with the increase of the basic radii of curvature and decreases with the increase of the target intraocular power. Among the multiple transition diffraction rings arranged radially, the radii of curvature of the outermost transition diffraction ring are substantially equal to the radii of curvature of the innermost transition diffraction ring.

2. The refractive-diffraction coupled full-range intraocular lens according to claim 1, characterized in that: The total number of diffraction rings on the front optical surface is 6 to 15, and the number of multiple sets of diffraction rings is 2 to 5.

3. The refractive-diffraction coupled full-range intraocular lens according to claim 1, characterized in that: The number of transition diffraction rings with decreasing curvature radii in each group of diffraction rings is one, and the number of diffraction rings with substantially equal curvature radii in each group of diffraction rings is two.

4. The refractive-diffraction coupled full-range intraocular lens according to claim 2, characterized in that: The number of diffraction rings is 10, and they are arranged radially from the inside to the outside as the first diffraction ring to the tenth diffraction ring; The first diffraction ring and the second diffraction ring have basically the same radius of curvature. The third diffraction ring is a transition diffraction ring, and its radius of curvature is 2mm to 7mm smaller than that of the first and second diffraction rings. The curvature radii of the fourth and fifth diffraction rings are basically equal. The sixth diffraction ring is a transition diffraction ring, and its curvature radius is 2mm to 7mm smaller than that of the fourth and fifth diffraction rings. The curvature radii of the seventh diffraction ring are basically equal to those of the eighth and ninth diffraction rings. The tenth diffraction ring is a transition diffraction ring, and its curvature radius is 2 mm to 7 mm smaller than that of the seventh, eighth, and ninth diffraction rings. The radius of curvature of the tenth diffraction ring is approximately equal to that of the third diffraction ring.

5. A refractive-diffraction coupled full-range intraocular lens according to claim 4, characterized in that: The outer boundary radii of the first diffraction ring to the tenth diffraction ring are respectively: First diffraction ring: 0.73mm~0.80mm; Second diffraction ring: 1.05mm~1.10mm; Third diffraction ring: 1.47mm~1.50mm; Fourth diffraction ring: 1.65mm~1.70mm; Fifth diffraction ring: 1.85mm~1.90mm; Sixth diffraction ring: 2.07mm~2.10mm; Seventh diffraction ring: 2.19mm~2.25mm; Eighth diffraction ring: 2.32mm~2.41mm; Ninth diffraction ring: 2.45mm~2.55mm; Tenth diffraction ring: 3.0 mm.

6. The refractive-diffraction coupled full-range intraocular lens according to claim 1, characterized in that: Among the multiple diffraction rings of the front optical surface, the odd-numbered diffraction rings have diffraction steps at their ends, and the even-numbered diffraction rings are smoothly connected to the adjacent odd-numbered diffraction rings; the height of the diffraction steps is a uniform value.

7. The refracting-diffraction coupled full-range intraocular lens according to claim 6, characterized in that: Even-numbered diffraction rings are smoothly connected to adjacent odd-numbered diffraction rings to eliminate stray light caused by structural abrupt changes.

8. The refractive-diffraction coupled full-range intraocular lens according to claim 1, characterized in that: The modulation transfer function of the far-field, mid-field, and near-field focal points differs by ≤15% at a spatial frequency of 50 lp / mm and a pupil diameter of 3 mm. Within the 0D to +3.0D defocus range, the modulation transfer function at a spatial frequency of 50 lp / mm is ≥0.

2.

9. A refractive-diffraction coupled full-range intraocular lens according to claim 8, characterized in that: The light energy distribution ratio of the far-field focus, the medium-field focus, and the near-field focus is 4:3:

3.

10. A refractive-diffraction coupled full-range intraocular lens according to claim 8, characterized in that: The diameter of the optical surface of the optical body is 5.5mm to 6.5mm; the radius of curvature of the rear optical surface is 15mm, 20mm or 25mm.

11. A method for designing a refractive-diffraction coupled full-range intraocular lens, used to design the intraocular lens as described in any one of claims 1 to 10, characterized in that, Includes the following steps: The basic spherical radius of curvature of the optical surface is selected based on the material of the intraocular lens and the target intraocular optical power. The basic spherical radius of curvature of the anterior optical surface is determined based on the target intraocular optical power, the anterior optical surface optical power, the posterior optical surface optical power, the material refractive index, and the intraocular medium refractive index. With the goal of achieving a modulation transfer function ≥0.4 at a spatial frequency of 100 lp / mm under a pupil diameter of 3 mm and at the far focal point of 0D, and controlling the spherical aberration of the entire field of view within ±0.05 μm, the front optical surface is optimized using an even-order aspherical formula to obtain the basic aspherical front optical surface. Diffraction rings are added to the optical surface of the basic aspherical surface, wherein the initial boundary position and step height of each diffraction ring are obtained based on the focal length corresponding to the near-distance additional optical power. Each diffraction ring of the front optical surface is set as an independent aspherical surface. With the goal of the modulation transfer function difference at the three focal points of far focal point 0D, mid focal point +1.5D, and near focal point +3.0D being ≤15% and the modulation transfer function not lower than 0.2 in the defocus range of 0~+3.0D, the aspherical surface of each independent aspherical surface is optimized by using the even-order aspherical surface formula to obtain the final boundary position and radius of curvature of each diffraction ring.

12. The design method of the refracting-diffraction coupling type full-range intraocular lens according to claim 11, characterized in that, The formula for even-order aspherical surfaces is as follows: Where r is the radial coordinate, R is the radius of curvature of the basic sphere, and k is the quadratic surface coefficient. Here are the coefficients of the higher-order terms of the aspherical surface, and n is a natural number not less than 1.

13. The design method of the refracto-diffraction coupled full-range intraocular lens according to claim 11, characterized in that: The initial boundary position of the diffraction ring is determined by the following formula: rm = Where rm is the outer boundary radius of the m-th diffraction ring, m is the diffraction ring order, λ is the incident light wavelength, and f' is the lens focal length; The step height of the diffraction ring is determined by the following formula: in, λ0 = 0.00055, where n1 is the refractive index of the intraocular lens material when immersed in the eye, n2 is the refractive index of the aqueous humor or vitreous medium in the eye.

14. The design method of the refracto-diffraction coupled full-range intraocular lens according to claim 11, characterized in that, The following formula is used to determine the basic spherical radius of curvature of the anterior optical surface based on the target intraocular optical power, the anterior optical surface optical power, the posterior optical surface optical power, the material refractive index, and the intraocular medium refractive index: F = Ff + Fb (tc / n1) Ff Fb; where F is the overall intraocular optical power of the intraocular lens, Ff is the single-surface optical power of the anterior surface, Fb is the single-surface optical power of the posterior surface, tc is the central optical thickness of the intraocular lens, n1 is the refractive index of the intraocular lens material under intraocular immersion conditions, and n2 is the refractive index of the aqueous humor or vitreous medium; Ff=(n1 n2) / ra,Fb=( n2 n1) / rb, where ra is the radius of curvature of the base spherical surface of the front optical surface and rb is the radius of curvature of the base spherical surface of the rear optical surface.

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