Multifocal ophthalmic lens

Abstract

Examples of a multi-focal ophthalmic lens are provided in this document. The lens includes: a base lens having a base arc corresponding to a base power; and a diffractive structure including a plurality of annular echelle gratings, the plurality of annular echelle gratings being formed on the first surface of the base lens. The diffractive structure is configured to produce: a zero order diffraction corresponding to a distant focus determined by a base power, the diffraction efficiency of the zero order diffraction being between 45% and 55%; first-stage diffraction, wherein the diffraction efficiency of the first-stage diffraction is between 5% and 10%; the second-stage diffraction corresponds to the focus in vision, and the diffraction efficiency of the second-stage diffraction is between 15% and 20%; and the third-stage diffraction corresponds to the perifocus, and the diffraction efficiency of the third-stage diffraction is between 15% and 25%. The diffractive structure includes a plurality of annular diffractive steps, each annular diffractive step defined by a profile having a curved ramp and a peak.

Description

Cross-references to related applications

[0001] This application claims priority to U.S. Provisional Application No. 63 / 585,409, filed September 26, 2023, entitled "MULTIFOCAL OPHTHALMIC LENSES," and U.S. Provisional Application No. 63 / 660,654, filed June 17, 2024, also entitled "MULTIFOCAL OPHTHALMIC LENSES." The entire contents of the above-cited applications are incorporated herein by reference. Technical Field

[0002] The invention set forth in the appended claims generally relates to ophthalmic devices, including but not limited to intraocular lenses (“IOLs”) for placement in the human eye. Background Technology

[0003] The human eye can be affected by a variety of conditions, ranging from mild vision loss to complete blindness. While contact lenses and glasses can compensate for some conditions, others may require eye surgery. In some cases, implants may be beneficial or desirable. For example, intraocular lenses can replace the cloudy natural lens inside the eye to improve vision. Although the benefits of intraocular lenses and other implantable devices are known, improvements will continue to be made to enhance treatment outcomes and benefit patients. Summary of the Invention

[0004] A multifocal ophthalmic lens is disclosed having a diffraction element consisting of a plurality of annular diffraction steps, each annular diffraction step being defined by a profile having a curved ramp and a peak, and having a diffraction efficiency of less than 10 percent for at least one diffraction order, substantially as shown and described in connection with at least one figure, and more fully set forth in the claims. Attached Figure Description

[0005] The accompanying drawings illustrate some objects, advantages, and preferred modes of implementing and applying the claimed subject matter. In the examples, the same reference numerals denote the same parts.

[0006] Figure 1 An intraocular lens according to an example embodiment is shown;

[0007] Figure 2 A side view depicting the surface profile of a diffraction structure on an exemplary multifocal ophthalmic lens according to some example embodiments;

[0008] Figure 3 Energy efficiency curves are plotted according to some example embodiments, demonstrating the effectiveness of energy utilization for... Figure 2The energy distribution of an exemplary surface profile across a series of focal lengths;

[0009] Figure 4 Depicting a specific embodiment of the target Figure 2 The visual sensitivity of an exemplary surface profile at a range of focal lengths;

[0010] Figure 5 Depicting an application of some exemplary embodiments Figure 2 A graphical representation of the monochromatic light modulation transfer function (“MTF”) of an exemplary surface profile of an IOL at a series of focal lengths; and

[0011] Figure 6 Depicting an application of some exemplary embodiments Figure 2 Another graphical representation of the exemplary surface profile of the IOL in terms of the monochromatic light modulation transfer function (“MTF”) over a series of focal lengths. Detailed Implementation

[0012] The following description of exemplary embodiments provides information that enables those skilled in the art to implement and apply the subject matter set forth in the appended claims, but some details well known in the art may be omitted. Therefore, the following description should be considered illustrative rather than restrictive.

[0013] This document may also describe exemplary embodiments with reference to the spatial relationships or spatial orientations of the various elements depicted in the accompanying drawings. Typically, such relationships or orientations employ a frame of reference consistent with or relevant to the patient. However, as those skilled in the art will recognize, such a frame of reference is merely a descriptive expedient and not a strict specification.

[0014] Figure 1 An example embodiment of an ophthalmic lens is shown, which has the feature of being configured to generate multiple focal points to provide a range of vision. More specifically, Figure 1 A multifocal diffractive intraocular lens (IOL) 100 is illustrated. The IOL 100 may include an optics element 104, which may include a diffractive structure 102. The IOL 100 may also include one or more loops 106 that can hold the IOL in place when it is implanted in the eye. For example, one or more loops 106 can achieve stable fixation of the IOL 100, and more specifically, the optics element 104, within the capsular bag. Although Figure 1 The example depicts an IOL 100 for implantation in the eye (e.g., in a capsular bag or ciliary sulcus), but other ophthalmic lenses (including multifocal diffractive contact lenses and multifocal diffractive glasses) incorporating similar diffractive structures 102 are also envisioned.

[0015] Optical device 104 can be manufactured from biocompatible materials such as modified poly(methyl methacrylate) (PMMA), modified PMMA hydrogel, hydroxyethyl methacrylate (HEMA), PVA hydrogel, other silicone polymer materials, and hydrophobic acrylic polymer materials, such as AcrySof® and Clareon® available from Alcon, Inc., FortWorth, Texas. The diameter of optical device 104... The diameter is between about 4.0 mm and about 8.0 mm, for example, about 6.0 mm. Optical device 104 can have various shapes and curvatures within the scope of this disclosure. For example, optical device 104 can have a front surface and a rear surface, each of which is convex, thus giving optical device 104 a biconvex shape. In other examples, optical device 104 can have a plano-convex shape, a convex-concave shape, or a plano-concave shape.

[0016] One or more loops 106 may include hollow radially extending struts that are joined (e.g., glued or welded) to or formed together with a portion of the optics 104 and thus extend outward from the optics 104 to engage with the peripheral wall of the eye's pouch, thereby maintaining the optics 104 in a desired position within the eye. The loops 106 may be made of biocompatible materials such as modified poly(methyl methacrylate) (PMMA), modified PMMA hydrogel, hydroxyethyl methacrylate (HEMA), PVA hydrogel, other silicone polymer materials, and hydrophobic acrylic polymer materials, such as AcrySof® and Clareon® available from Alcon, Fort Worth, Texas, USA. The loops 106 may typically have radially outward ends defining an arcuate end portion. The end portion of the loops 106 may be spaced apart by a length L between about 6 mm and about 22 mm, for example, spaced apart by about 13 mm. Loop 106 has a specific length that allows for slight engagement pressure at the distal end when it contacts the equatorial region of the capsule after implantation. Although Figure 1 An example configuration of loop 106 is depicted, but any plate loop or other type of loop can be used.

[0017] Further reference Figure 1The IOL 100 can be a multifocal IOL (having multiple focal points, such as bifocal, trifocal, tetrafocal, and pentafocal), characterized by an optical element 104 and a diffraction structure 102, the optical element having a base arc, the diffraction structure being formed on the base arc of the optical element 104. The base arc of the optical element 104 determines the fundamental optical power (referred to simply as "fundamental power") of the IOL 100, which can correspond to a distance focal power used to provide distance vision. Alternatively, the fundamental power can correspond to an optical power other than a distance focal power, such as an optical power corresponding to near or intermediate vision. The optical element 104 can have a front surface and a rear surface, either of which can have a base arc corresponding to the fundamental power. Figure 1 In the example, the diffraction structure 102 is formed on the front surface of the optical device 104. However, in other embodiments (not shown), the diffraction structure 102 may be formed on the rear surface or on both the front and rear surfaces, or within the body of the optical device 104.

[0018] The diffraction structure 102 may include a plurality of annular echettes 103 surrounding the central region of the optical device 104. For example, a first circular echette may be centered on the optical axis of the optical device 104 and have a minimum radius. A second annular echette may be adjacent to the first circular echette and may also be centered on the optical axis of the optical device 104, with a radius larger than the minimum radius. A third annular echette may be adjacent to the second annular echette and may also be centered on the optical axis of the optical device 104, with a radius larger than the radius of the second annular echette. The plurality of annular echettes 103 may include any number of echettes, for example, about 6 to 30 echettes. In some embodiments, the plurality of annular echettes 103 may include 12 to 20 echettes, 14 to 18 echettes, or about 15 echettes.

[0019] Each of the multiple annular eddy gratings 103 may have a sag height, which is the distance from the base arc of the optical device 104.

[0020] The diffraction structure 102 can distribute incident light energy onto the front surface of the IOL 100 to multiple different focal points corresponding to different diffraction orders. For example, the diffraction structure 102 can diffract the incident light and produce constructive interference in multiple diffraction orders associated with multiple focal points, so that the light energy, power, or intensity of the incident light can be distributed to these multiple diffraction orders. Therefore, the diffraction efficiency of each diffraction order can be less than 100%. In some exemplary embodiments, the diffraction structure 102 can distribute light energy to at least four different focal points corresponding to different diffraction orders. Zero-order diffraction (i.e., light energy is directly transmitted through the fundamental arc of the optics 104) can provide a line of sight determined by the fundamental arc of the optics 104.

[0021] In some embodiments, one or more diffraction orders may not correspond to any desired focus; therefore, the light energy originally associated with such one or more diffraction orders may be diverted or distributed to one or more other diffraction orders (which may correspond to one or more desired focuses). For example, in some embodiments, a first-order diffraction may not correspond to any desired focus and may be diverted to one or more other diffraction orders. In some cases, it can be considered that the light energy corresponding to the first-order diffraction is designed to be minimized or “suppressed” so that the energy can be distributed to one or more other diffraction orders. Some embodiments may additionally or alternatively perform energy allocation between diffraction orders such that one diffraction order receives only a portion of the light energy originally allocated to it to provide at least some vision at a particular focus, while still allowing the majority of the energy associated with that corresponding diffraction order to be diverted or distributed to one or more other diffraction orders.

[0022] As envisioned above, in some embodiments, the diffraction structure 102 can distribute incident light energy to at least four different diffraction orders corresponding to different visual focal points. In some embodiments, the zero diffraction order can be used to provide distance vision, the first diffraction order may be expected to have relatively less distributed light energy compared to the other three expected diffraction orders or be considered to be partially suppressed, and the second and third order diffractions provide intermediate and near focal points, respectively.

[0023] In some examples, diffraction order and / or focus are described numerically, such as 0th diffraction order, 1st diffraction order, 2nd diffraction order, and / or 3rd diffraction order (as per [reference to diffraction order]). Figure 2 (Examples are explained in more detail below). However, the descriptors are not limited to this, allowing diffraction orders and their associated structural and / or physical components to be described by any number or kind of convention. Furthermore, some examples of multifocal IOLs are described herein as tetrafocal. However, the number of focal points and the number of diffraction orders can differ (e.g., larger or smaller). For example, some features may not be described as diffraction orders but still contribute to the total amount of energy transmitted to the patient's eye.

[0024] In particular, some example IOLs are multifocal rear chamber IOLs that use multiple diffraction orders (i.e., 0 diffraction order, +1 diffraction order, +2 diffraction order, +3 diffraction order), where the light energy assigned to the +1 diffraction order is reduced or minimized. For example, this four-order embodiment can use different successive diffraction orders, such as starting with diffraction orders from -4 to +2 diffraction orders. And while including the zero order may be desirable for distance vision, this condition is not a necessary constraint for defining diffraction orders (e.g., diffraction orders arranged in a repeating pattern on the surface of the IOL). Finally, this approach can, in principle, be applied to more than four diffraction orders; for example, a five-order diffraction lens can have multiple powers, including two intermediate powers, a near power, and a minimum energy or suppressed intermediate power.

[0025] In some embodiments, the focal point may be located at a distance between 50 cm and 80 cm from the eye, or in some more specific embodiments, between 60 cm and 70 cm. For example, the focal point may be located at approximately 60 cm, which is within the optical range for performing tasks using a digital screen. In some embodiments, the near focal point may be located at a distance between 30 cm and 50 cm, or in some more specific embodiments, between 30 cm and 40 cm. For example, the focal point may be located at approximately 40 cm, which is an ideal distance for reading and other near-field tasks.

[0026] The distribution of incident light energy toward the far, intermediate, and near focal points (referred to as "diffraction efficiency") can be adjusted by modifying the configuration of the annular eddy gratings. For example, in some embodiments, to provide the desired diffraction efficiency toward the far, intermediate, and near focal points, the radial spacing of the annular eddy gratings relative to each other and / or the sag of each eddy grating can be adjusted.

[0027] In some examples of quadfocal IOLs, the first-order diffraction can be similarly adjusted. Since the first-order diffraction may not correspond to the desired focal point in some lenses, the diffraction efficiency of the first-order diffraction can be intentionally designed to be minimized or suppressed. This can be achieved by configuring the echelle grating to limit the energy distributed to the first-order diffraction, thereby allowing more energy of the incident light to be distributed or assigned to other diffraction orders.

[0028] As disclosed herein, by adjusting the configuration of the echelle grating, the overall diffraction efficiency of the lens can be improved. Therefore, some additional energy of the incident light can be allocated to the focal point associated with the first diffraction order, thereby enhancing the bridging energy between the zeroth-order diffraction (e.g., the fundamental focal point) and the second-order diffraction (e.g., the central focal point). For example, in some embodiments, it may be desirable to allocate approximately 5% to 10% of the total energy intensity to the first diffraction order to achieve a smooth transition from distance to central vision.

[0029] For example, by customizing the amount of energy allocated to the first diffraction order, the total energy distribution on the IOL increases. Advantageously, the energy and focusing ability at the distance, intermediate, and near focal points remain strong. In other words, the total energy transmitted to the patient's eye increases while avoiding a noticeable gap between the distance and intermediate focal points. Consequently, the patient enjoys enhanced vision while experiencing a smooth transition between the distance and intermediate focal points.

[0030] In a particular embodiment, the parameters are selected such that the +1 order is at least partially suppressed. In other words, the proportion of light energy at the +1 order is reduced relative to the distribution of total light energy among several diffraction orders intended to provide a useful visual focus, causing the image at the focal point corresponding to the +1 order to become less clearly focused. This reduction in light energy may correspond to approximately 15% less than the incident light energy, or in some embodiments, less than 10%. The proportion of incident light energy focused at a particular order is called the "diffraction efficiency." Therefore, the diffraction efficiency at the +1 diffraction order is less than that at the 0, +2, and +3 diffraction orders, approximately 10% or less.

[0031] The optical surface profile (including the diffraction structure 102) of the optical device 104 can be defined, at least in part, mathematically. The optical surface profile of the multifocal lens defines the diffraction structure 102, and thus defines the lens's energy distribution and diffraction efficiency. As an example, the sag of the surface profile of the optical device 104 can be defined by the following formula: In the formula, zasp and zdiff are the aspherical component and diffraction component of the sag, respectively.

[0032] The aspherical component (z) of the surface profile of optical device 104 asp This can be mathematically described as: 0.0 ≤ r ≤ 3.0 In the formula, c is the curvature of the surface (i.e., the reciprocal of the radius), k is the conic constant, and r is the radial distance from the optical center.

[0033] The diffraction component (z) of the surface profile of optical device 104diff It can be mathematically described based on the following variables, values, and formulas (including those included in Tables 1 through 3). Table 1: Constants used in the definition of height The upper boundary of region n (in millimeters) is defined as: Given the distance (r) from the optical center and the zone identifier (n), the sag (in millimeters (mm) can be calculated using the following formula: , In the formula, w (wavelength to millimeter conversion constant) and x are: and In the formula, A, B, and C are the phase offsets; H is the phase offset; A, B, and C are amplitude coefficients with values ​​between -1 and +1; and S(n) is the individual phase offset for each individual epoch grating. Further, H, A, and B define the repeatability profile (e.g., three toothed or epoch gratings as a group, and this group is repeated five times). In some examples, the step height (S) provides the degree of freedom to assign a unique phase offset to each peak / epoch grating. Details of the variables S, H, A, and B are listed in Tables 2 and 3. Table 2: Variables used in the definition of height Table 3: H, A, and B values ​​for each segment identifier

[0034] Figure 2 A side view of the diffraction vector profile 10 of an example diffraction structure 102 according to some illustrative embodiments is shown. Figure 2 An exemplary diffraction vector profile can be generated from the vector formulas and representative values ​​discussed above. For example, diffraction vector profile 10 is calculated according to the formula described above, which includes elements... This can produce curved ramps in one or more diffraction eddy gratings, and can exist in each diffraction eddy grating. Therefore (as...) Figure 2 (As provided in the text), curvature can affect the angle of incidence at each diffraction order, which in turn affects the amount of energy transmitted through it.

[0035] The curvature elements used to define the transmittance at the first diffraction order help to obtain appropriate bridging energy between the distance focus and the intermediate focus, thus improving the overall energy utilization across the entire annular echelle grating. For example, the sag formula described above provides a sag profile with curvature elements that can be repeated on the surface of the lens. While some examples generally show parabolic curves with increased curvature at one or more transition points (e.g., peaks or valleys of the diffraction sag profile), in some examples, any curvature may be less pronounced. Furthermore, one or more diffraction orders can be defined by substantially linear portions. In each embodiment, the relatively limited diffraction efficiency at the first diffraction order (e.g., between the distance focus and the intermediate focus) helps to enhance the overall energy transmittance and act as a bridge between the two.

[0036] exist Figure 2 In the graph, the horizontal axis r depicts the radial distance extending outward from the center of the optical device 104 toward the peripheral portion or outer edge of the optical device 104. Figure 2 The vertical axis of the curve corresponds to the sag height (or sag for short) of each step grating. For example... Figure 2 The diffraction height profile shown may include a repeatable structure with three segments or eddy gratings, which may be repeated over 15 zones, for a total of 15 eddy gratings. As previously discussed, the exemplary diffraction structure 102 may be configured to distribute light energy to four diffraction orders, thereby making the optics 104 and IOL 100 a four-focal design.

[0037] like Figure 2 As shown, in some embodiments, a repeatable structure with three step gratings may include: a first step grating with a first step height 12, a second step grating with a second step height 16, and a third step grating with a third step height 20. As shown, the second step height 16 may be between one-quarter and half the height of the first step height 12 of the first step grating. Figure 2 As further shown, the height of the third step 20 can be less than the height of the second step 16.

[0038] Advantageously, the sag profile 10 is defined by one or more curves along the inclined or lateral portion. Figure 2In the example, a portion 22 of the sag profile 10 rises in a curved manner toward the first step height 12. The sag profile 10 continues, with portion 24 descending with a substantially linear, substantially vertical ramp, and then rising via portion 26 toward the second step height 16. Although the term "linear" is used to describe some portions of the sag profile and / or diffraction order, portions 24 (and / or 28, 32) may have moderate or more pronounced curvature. Typically, portions 22, 26, and 30 are represented as having a greater amount of curvature than portions 24, 28, and 32. As shown, the rise of portion 26 is approximately linear, becoming gradually more curved as portion 26 approaches the next peak of the sag profile 10 at the second step height 16. Another portion 28 descends from the second step height 16 and then rises as a curved portion 30 to reach the next peak at the third step height 20. Figure 2 In the example, this pattern can be repeated, specifically as follows: the curved portion rises to a peak step height, followed by a substantially linear downward portion. As shown, the distances between the first step heights (e.g., between first step heights 12 and 12A, between first step heights 12A and 12B, between first step heights 12B and 12C, and between first step heights 12C and 12D) decrease as the ring radius increases, thus providing a denser pattern. Therefore, according to the sag formula provided herein, the curvature of the rising portion becomes steeper.

[0039] As shown in the figure, the curved portion of the sag profile (e.g., ramps 22, 26, 30) faces the center of the lens (e.g., the ring radius towards 0 mm). In effect, the surface of the curved portion receives incident light corresponding to the eye's focal point. Therefore, the incident light enters the lens at the curved surface, thus providing a different light energy distribution profile than a substantially flat surface.

[0040] Opposite to the curved surface (e.g., relative to the peak or step height) is a substantially linear portion (e.g., ramps 24, 28, 32). The linear portion is away from the center of the lens (e.g., toward the edge of the lens). Light rays from objects surrounding the eye can enter the lens through the linear portion.

[0041] For an IOL employing example height profile 10, the energy of the incident light is distributed across four diffraction orders, increasing the overall energy utilization. The first diffraction order receives less energy relative to the other diffraction orders, while providing bridging energy between the zero diffraction order / distant focal point and the second diffraction order / central focal point.

[0042] Figure 3 The energy utilization rate curve 30 is plotted, showing the effect of... Figure 2 The diffraction efficiency is calculated based on the four diffraction orders corresponding to the exemplary diffraction vector height surface profile 10. For example... Figure 3 What is shown Figure 2 The diffraction vector profile can produce four distinct energy peaks, corresponding to four diffraction orders (e.g., 0th diffraction order 32, 1st diffraction order 34, 2nd diffraction order 36, and 3rd diffraction order 38). In some embodiments, approximately 40% to 55% (or 48% in some embodiments) of the incident light energy can be distributed to the 0th diffraction order, which corresponds to the distance of vision. In some embodiments, approximately 15% to 25% (or 21% in some embodiments) of the light energy can be distributed to the 3rd diffraction order, which corresponds to the near distance (e.g., 40 cm focal length), and approximately 10% to 20% (or 17% in some embodiments) of the light energy can be distributed to the 2nd diffraction order, which corresponds to the middle distance (e.g., 60 cm focal length). Additionally, approximately 5% to 10% (or 9% in some embodiments) of the incident light energy can be distributed to the 1st diffraction order, which corresponds to the distance of vision at a focal length between the distance and near distance. Although the amount of light energy distributed to the first diffraction order can be less than that distributed to other diffraction orders, the light energy distributed to the first diffraction order can act as bridging energy to achieve a smooth visual transition between distance and central vision. Therefore, the performance between the 0th diffraction order and the 2nd diffraction order is enhanced, which may be due to the increased total energy utilization of the disclosed IOL.

[0043] Table 4 below shows several energy ranges for the disclosed diffraction structures according to different embodiments. As provided below, several embodiments of a multifocal IOL having diffraction orders generated by the above formulas were tested for energy transmission distribution. For example, in the following example embodiments, the total energy transmitted through the diffraction structure may be close to but less than 100%. As shown, the total energy in some embodiments includes part or all of the energy corresponding to each diffraction order of a multifocal IOL having four diffraction orders. The largest amount of energy is assigned to the 0th diffraction order (at the distance focus), while the smallest amount of energy is assigned to the 1st diffraction order (at the bridging focus between the distance focus and the intermediate focus). Table 4: Energy efficiency values ​​(percentage of total transmitted energy per diffraction order):

[0044] As a result, patients enjoy enhanced vision while experiencing a smooth transition between the distant and intermediate focal points.

[0045] Figure 4 Describing the target Figure 2 The exemplary diffraction vector height surface profile and its visual acuity at a range of focal lengths are shown. The range of visual acuity is illustrated for defocusing from +1.0 D (mesoscopic side) to -3.0 D (mysoscopic side). Figure 4 The curve graph shows that Figure 2The diffraction vector height surface profile can provide a high level of visual acuity extending from far to near vision.

[0046] Figure 5 Depicting an application of some exemplary embodiments Figure 2 The exemplary surface profile of the IOL is graphically represented by the monochromatic light modulation transfer function (“MTF”) over a range of focal lengths. Graph 40 shows test results for a 4.5 mm pupil at 100 line pairs per millimeter (Lp / mm), providing a representative measure of the resolution of lens 100. For example, the more line pairs per millimeter (lp / mm), the higher the lens spatial resolution, and thus the more fine details in the image can be resolved.

[0047] As shown in the figure, each diffraction order produces a different resolution. Plot 40 shows four peaks representing the metric of MTF, each peak corresponding to a different resolution. Figure 2 The diffraction vector height profile generates one of four different diffraction orders (e.g., 0th diffraction order 42, 1st diffraction order 44, 2nd diffraction order 46, and 3rd diffraction order 48). However, in some examples, the diffraction orders may not map to the number and / or size of the echelle gratings. For example, several echelle gratings (e.g., two, three, four, five, or six) may work together to split and / or distribute the light transmitted to the eye into multiple diffraction orders.

[0048] In some embodiments, the MTF corresponding to the 0th diffraction order is approximately 0.30 to 0.35, or 0.33 in some embodiments. In some embodiments, the MTF corresponding to the second diffraction order is approximately 0.10 to 0.15, or 0.13 in some embodiments. In some embodiments, the MTF corresponding to the third diffraction order is approximately 0.15 to 0.20, or 0.18 in some embodiments. Additionally, the MTF corresponding to the first diffraction order (which may correspond to the distance at a focal length between near and far vision) is approximately 0.01 to 0.06, or 0.04 in some embodiments.

[0049] As explained in this paper, the amount of light energy distributed to the first diffraction order can be less than the amount of light energy distributed to other diffraction orders (and therefore the resolution is also lower), thus acting as a relatively gentle bridge to achieve a smooth visual transition between distance and intermediate vision, thereby enhancing performance between the 0th and 2nd diffraction orders.

[0050] Figure 6 Depicting an application of some exemplary embodiments Figure 2 A graphical representation of the monochromatic light modulation transfer function (“MTF”) of an exemplary surface profile of the IOL at a series of focal lengths. Although similar to… Figure 5The curve 40 (representing the MTF for a 4.5 mm pupil), but Figure 6 This represents the MTF at 100 lp / mm for a 3.0 mm pupil. Therefore, graph 50 shows four peaks representing the measure of MTF, each peak corresponding to a value derived from... Figure 2 One of four different diffraction orders (e.g., 0th diffraction order 52, 1st diffraction order 54, 2nd diffraction order 56, and 3rd diffraction order 58) is generated by the diffraction vector height profile. For example, the more line pairs per millimeter (lp / mm), the higher the lens spatial resolution, and thus the finer details in the image can be resolved.

[0051] In the disclosed example, the multifocal ophthalmic lens includes: an optics having a base arc corresponding to the fundamental power; and a diffraction element that produces constructive interference in at least four consecutive diffraction orders, wherein the constructive interference produces a near focal point, a far focal point, and a central focal point between the near and far focal points, and wherein the diffraction element includes a plurality of annular diffraction steps, two or more of which are defined by a profile having curved ramps and peaks, and at least one diffraction order has a diffraction efficiency of less than 10 percent.

[0052] In some examples, each of the multiple annular diffraction steps of a multifocal ophthalmic lens has a curved ramp, a peak, and a linear ramp.

[0053] In the example, the multiple annular diffraction steps of the multifocal ophthalmic lens include a repeating set with three step gratings.

[0054] In the example, the first ramp of the multifocal ophthalmic lens has a curved edge that approximates a peak corresponding to one or more diffraction steps, the first ramp corresponding to a diffraction height profile with at least four consecutive diffraction orders.

[0055] In some examples, each of the multiple annular diffraction steps of a multifocal ophthalmic lens has a less pronounced slope relative to the curved edge.

[0056] In some examples, the curved edge faces the center of the multifocal ophthalmic lens.

[0057] In some examples, the linear ramp faces the outer edge of the multifocal ophthalmic lens.

[0058] In some examples, the diffraction efficiency of the first diffraction order is between five percent and nine percent.

[0059] In some examples, the diffraction efficiency of the first diffraction order is nine percent.

[0060] In some examples, the lens is an intraocular lens (IOL).

[0061] In some examples, at least four consecutive diffraction orders are 0 diffraction order, +1 diffraction order, +2 diffraction order, and +3 diffraction order.

[0062] In some examples, the diffraction efficiency of the +1 diffraction order is suppressed.

[0063] In some examples, the near focal point corresponds to visual acuity at 40 cm, and the intermediate focal point corresponds to visual acuity at 60 cm.

[0064] In some examples, the diffraction efficiency of the zeroth-order diffraction is between 45% and 50%; the diffraction efficiency of the first-order diffraction is between 7% and 9%; the diffraction efficiency of the second-order diffraction is at least between 15% and 20%; and the diffraction efficiency of the third-order diffraction is between 19% and 23%.

[0065] In some examples, the total energy efficiency through the diffraction element is greater than 90%.

[0066] In some of the disclosed examples, the multifocal ophthalmic lens includes: an optics having a base arc corresponding to the fundamental power; and a diffraction element that produces constructive interference in at least four consecutive diffraction orders, wherein the constructive interference produces a near focal point, a distance focal point, and an intermediate focal point between the near and distance focal points, and wherein the diffraction element has a diffraction height profile defined by the following formula:

[0067] In the formula, r is the distance from the optical center, n is the zone identifier, w is the wavelength to millimeter conversion constant, H is the phase shift, x is calculated based on r, A, B and C are amplitude coefficients with values ​​between -1 and +1, and S(n) is the individual phase shift of each individual grating.

[0068] In some examples, x is calculated using the following formula:

[0069] In the formula, n is the refractive index of the diffraction ring, and Rn is the radius of the nth diffraction grating.

[0070] In some examples, w is calculated using the following formula:

[0071] In the formula, RIL is the refractive index of the lens, and RIM is the refractive index of the medium that constitutes the multifocal ophthalmic lens.

[0072] In some examples, the first-order diffraction has a diffraction efficiency of 8%.

[0073] In some examples, the lens is an intraocular lens (IOL).

[0074] Although illustrated only in illustrative embodiments, those skilled in the art will recognize that the systems, devices, and methods described herein are susceptible to a wide variety of changes and modifications. Furthermore, descriptions of multiple different alternatives using terms such as "or" are not required to be mutually exclusive unless the context explicitly requires it, and the indefinite article "a / an" does not limit the subject matter to a single example unless the context explicitly requires it. Components may also be combined or removed in a variety of different configurations for purposes of sale, manufacture, assembly, or use.

[0075] The claims may also cover additional subject matter not specifically detailed. For example, certain features, elements, or aspects may be omitted from the claims if it is not necessary to distinguish novel and inventive features from those known to a person skilled in the art. Features, elements, and aspects described in the context of some embodiments may also be omitted, combined, or replaced by alternative features for the same, equivalent, or similar purposes without departing from the scope of the invention as defined by the appended claims.

Claims

1. A multifocal ophthalmic lens, comprising: An optical device having a base arc corresponding to the base power; as well as A diffraction element that produces constructive interference in at least four consecutive diffraction orders, wherein the constructive interference produces a near focal point, a far focal point, and a mid-focal point between the near and far focal points. The diffraction element comprises multiple annular diffraction steps, two or more of which are defined by a profile with curved ramps and peaks. The diffraction efficiency of at least one diffraction order is less than 10 percent.

2. The multifocal ophthalmic lens as described in claim 1, wherein, Each of the plurality of annular diffraction steps has a curved ramp, a peak, and a linear ramp.

3. The multifocal ophthalmic lens as described in claim 2, wherein, The plurality of annular diffraction steps include a repeatable group with three step gratings.

4. The multifocal ophthalmic lens as described in claim 3, wherein, The first ramp has a curved edge approaching the peak of one or more diffraction steps, and the first ramp corresponds to a diffraction height profile with at least four consecutive diffraction orders.

5. The multifocal ophthalmic lens as described in claim 1, wherein, Each of the plurality of annular diffraction steps has a less pronounced slope opposite the curved edge.

6. The multifocal ophthalmic lens as described in claim 1, wherein, The curved edge faces the center of the multifocal ophthalmic lens.

7. The multifocal ophthalmic lens as described in claim 1, wherein, The linear ramp faces the outer edge of the multifocal ophthalmic lens.

8. The multifocal ophthalmic lens as described in claim 1, wherein, The diffraction efficiency of the first diffraction order is between 5% and 9%.

9. The multifocal ophthalmic lens as described in claim 1, wherein, The diffraction efficiency of the first diffraction order is nine percent.

10. The multifocal ophthalmic lens as claimed in claim 1, wherein, The lens is an intraocular lens (IOL).

11. The multifocal ophthalmic lens as described in claim 1, wherein, The at least four consecutive diffraction orders are the 0 diffraction order, +1 diffraction order, +2 diffraction order, and +3 diffraction order.

12. The multifocal ophthalmic lens as described in claim 11, wherein, The diffraction efficiency of the +1 diffraction order is suppressed.

13. The multifocal ophthalmic lens as described in claim 1, wherein, The near focal point corresponds to visual acuity at 40 cm, and the intermediate focal point corresponds to visual acuity at 60 cm.

14. The multifocal ophthalmic lens as described in claim 1, wherein, The diffraction efficiency of the zeroth-order diffraction is between 45% and 50%; the diffraction efficiency of the first-order diffraction is between 7% and 9%. The diffraction efficiency of the second-order diffraction is at least between 15% and 20%; and The diffraction efficiency of the third-order diffraction is between 19% and 23%.

15. The multifocal ophthalmic lens as described in claim 1, wherein, The total energy efficiency of the diffraction element is greater than 90%.

16. A multifocal ophthalmic lens, comprising: An optical device having a base arc corresponding to the base power; as well as A diffraction element that produces constructive interference in at least four consecutive diffraction orders, wherein the constructive interference produces a near focal point, a far focal point, and a mid-focal point between the near and far focal points. The diffraction element has a diffraction vector profile defined by the following formula: In the formula, r is the distance from the optical center, n is the zone identifier, w is the wavelength to millimeter conversion constant, H is the phase shift, x is calculated based on r, A, B and C are amplitude coefficients with values ​​between -1 and +1, and S(n) is the individual phase shift of each individual grating.

17. The multifocal ophthalmic lens as described in claim 16, wherein, x is calculated using the following formula: In the formula, n is the refractive index of the diffraction ring, and Rn is the radius of the nth diffraction grating.

18. The multifocal ophthalmic lens as described in claim 16, wherein, w is calculated using the following formula: In the formula, RIL is the refractive index of the lens, and RIM is the refractive index of the medium constituting the multifocal ophthalmic lens.

19. The multifocal ophthalmic lens as described in claim 16, wherein, The first-order diffraction has a diffraction efficiency of 8%.

20. The multifocal ophthalmic lens as claimed in claim 16, wherein, The lens is an intraocular lens (IOL).

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