Ophthalmic lenses with extended depth of focus

Abstract

The present disclosure relates to ophthalmic lenses with extended depth of focus. In certain embodiments, an ophthalmic lens (100) includes an optic (102) having a front surface (14), a back surface (106), and an optical axis (108). At least one of the front surface and the back surface includes: a first zone (112) extending from the optical axis to a first radial boundary; and a second zone (114) extending from the first radial boundary to an edge of the optic. The first zone includes an inner region (116) and an outer region (118) separated by a phase shift feature (120), the phase shift feature including ridges extending outwardly from the inner region and the outer region.

Description

[0001] This application is a divisional application of an invention patent application with an application date of February 15, 2017, application number 201780011250.7, and invention name “Ophthalmic lens with extended depth of focus”. Technical Field

[0002] The present disclosure relates generally to ophthalmic lenses, and more particularly to ophthalmic lenses having extended depth of focus. Background Art

[0003] Intraocular lenses (IOLs) are routinely implanted in the patient's eye during cataract surgery to replace the natural lens. The optical power of the natural lens can vary under the influence of the ciliary muscles, thereby providing accommodation for viewing objects at different distances from the eye. However, many IOLs provide a single focal power without providing accommodation. Multifocal IOLs are also known to provide both distance power and near power (e.g., by employing a diffractive structure), thereby providing a degree of pseudo-accommodation. However, there remains a need for improved IOLs that can provide pseudo-accommodative optical power. Summary of the invention

[0004] The present disclosure generally relates to ophthalmic lenses (e.g., IOLs) that provide (1) controlled variation of multiple phase shifts within a pupil region to extend depth of focus and (2) angular adjustment in a central subregion of the pupil region to shift a through focus curve and rebalance energy between intermediate and far corrections. In certain embodiments, an ophthalmic lens includes an optical device having a front surface, a back surface, and an optical axis. At least one of the front surface and the back surface includes: a first zone extending from the optical axis to a first radial boundary; and a second zone extending from the first radial boundary to an edge of the optical device. The first zone includes an inner region and an outer region separated by a phase shift feature, the phase shift feature including ridges extending outwardly from the inner region and the outer region. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] For a more complete understanding of the present disclosure and advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals indicate like features, and in which:

[0006] Figure 1A-1B An example embodiment of an intraocular lens with extended depth of focus according to certain embodiments of the present disclosure is presented;

[0007] Figure 2 A graph showing surface concavity versus radial distance from the optical axis for an exemplary optical device having inner and outer regions with the same base curvature according to certain embodiments of the present disclosure;

[0008] Figure 3Figure 2 shows a through-focus diagram of certain embodiments of the present disclosure compared to a standard aspheric optic. Figure 2 Through-focus diagram of the optical device surface profile depicted in ;

[0009] Figure 4 a graph showing surface concavity versus radial distance from an optical axis for an exemplary optical device having inner and outer regions with different base curvatures according to certain embodiments of the present disclosure; and

[0010] Figure 5 Certain embodiments of the present disclosure are shown Figure 2 The defocus diagram of the optics depicted in Figure 4 Through-focus diagram of the optical device surface profile depicted in .

[0011] Those skilled in the art will appreciate that the following drawings are for illustration purposes only. These drawings are not intended to limit the scope of the applicant's disclosure in any way. DETAILED DESCRIPTION

[0012] The present disclosure generally relates to an ophthalmic lens (such as an IOL) having a surface profile that produces controlled changes in the phase shift of light waves passing through different areas of the lens in a manner that extends the depth of focus. In the following description, lens features that provide extended depth of focus are described in conjunction with an intraocular lens (IOL). However, those features contemplated by the present disclosure may also be applied to other ophthalmic lenses, such as contact lenses. As used herein, the term intraocular lens (and its abbreviation IOL) is used to describe a lens that is implanted inside the eye to replace the eye's natural lens or otherwise enhance vision, regardless of whether the natural lens is removed.

[0013] Figure 1A-1B An example embodiment of an intraocular lens 100 with extended depth of focus according to certain embodiments of the present disclosure is shown; the IOL 100 includes an optic 102 including an anterior surface 104 and a posterior surface 106 arranged about an optical axis OA 108. The IOL 100 may further include a plurality of haptics 110 that are generally operable to position and stabilize the IOL 100 within the capsular bag of the patient's eye.

[0014] like Figure 1AAs shown in , the front surface 104 of the optical device 102 includes: a first zone 112, which extends from the optical axis 108 to a first radial boundary; and a second zone 114, which extends from the first radial boundary to the edge of the optical device 102. In addition, the first zone 112 may include an inner region 116 and an outer region 118 separated by a phase shifting feature 120. In general, the above-mentioned surface features of the optical device 102 can produce different amounts of phase shift of light waves passing through the optical device 102 (depending on the area of ​​the optical device 102 that the light waves pass through), and the structural interference between the light waves with different amounts of phase shift can produce an extended depth of focus. Although the above-mentioned first and second zones 112, 114 are depicted and described as being located on the front surface 104 of the optical device 102, the present disclosure contemplates that the first and second zones 112, 114 can be additionally or alternatively located on the back surface 106 of the optical device 102.

[0015] In some embodiments, the phase shifting feature 120 may include a ridge protruding forwardly from the front surface 104 of the optical device 102. Thus, moving radially outwardly from the optical axis 108, the phase shifting feature 120 may produce two phase shift steps. For example, the surface profile of the first zone may be defined by the following equation:

[0016] Z 第一区 =Z 基础 +Z 2ps Equation (1)

[0017] In equation (1), according to the following equation, Z 基础 The basic depression profile of the first zone can be defined:

[0018]

[0019] in,

[0020] r is the radial distance from the optical axis 108;

[0021] c is the base curvature of the first zone 112;

[0022] k is the cone constant; and

[0023] a2, a4, a6... and a n Correspondingly are the second, fourth, sixth...nth order coefficients.

[0024] In some embodiments, it is defined that Z 基础 The equation for Z can include only the second, fourth, and sixth order coefficients. In other words, according to the following equation, Z 基础 The basic depression profile of the first zone can be defined:

[0025]

[0026] Although equations (2) and (3) generally define an aspherical surface profile, the present disclosure contemplates that the constants included in those equations may be selected such that they define a spherical surface profile. In other words, the base curvature (Z) of the first zone is 基础 ) can be spherical or aspherical.

[0027] In equation (1), Z 2ps Can be added to the base concave profile (Z 基础 ) and may partially define the characteristics of the phase shift region 120. For example, Z 2ps It can be defined by the following equation:

[0028]

[0029] In the formula,

[0030] r is the radial distance from the optical axis 108;

[0031] r0 is the optical axis 108;

[0032] The inner region 116 extends from the optical axis 108 to r1

[0033] The phase shift feature 120 extends from r1 to r4;

[0034] The outer region 118 extends from r4 to r5;

[0035] Δ1 is the step height of the phase shift feature 120 relative to the inner region 116; and

[0036] Δ2 is the step height of the phase shift feature relative to the outer region 118 .

[0037] The overall surface profile of the optical device 102 defined by equations (1)-(4) can be graphically represented as a plot of concavity versus radial distance from the optical axis 108, as Figure 2 As shown in Figure 2 In the figure, we have removed Z 基础 The contribution of Z is used to normalize the concavity values ​​(i.e., the plotted concavity values ​​correspond only to 2ps ). In addition, Figure 2 , the concave profile is consistent for the first zone 112 and the second zone 114. In other words, assume that equation (1) defines the surface profile of the entire optical device 102 rather than just the first zone 112 (meaning that in equation (4), r5 corresponds to the radius of the entire optical device 102).

[0038] Figure 3 It is shown that certain embodiments according to the present disclosure are comparable to standard aspheric optics (i.e., having a surface defined only by equation (3) (Z 基础) is limited without adding equation (4)(Z 2ps )'s surface profile compared to the defocus map of the optical device Figure 2 Through-focus diagram of the optical device surface profile depicted in FIG. As shown, Figure 2 The surface contours depicted in 2ps The phase shifting features 120 shown result in a wider depth of focus than a standard aspheric lens.

[0039] In some embodiments, the base recess profile may be different for the first region 112 and the second region 114. For example, the surface profile of the optical device 102 may be defined by the following equation:

[0040] Z 光学器件 =Z 基础 +Z 2ps Equation (5)

[0041] In the formula,

[0042]

[0043]

[0044]

[0045] r is the radial distance from the optical axis 108;

[0046] r0 is the optical axis 108;

[0047] The first region 112 extends from the optical axis 108 to r5, wherein the inner region 116 extends from the optical axis 108 to r1, the phase shift feature 120 extends from r1 to r4, and the outer region 118 extends from r4 to r5;

[0048] The second region 114 extends from r5 to r6;

[0049] c is the base curvature of the first zone 112;

[0050] k is the cone constant of the first region 112; and

[0051] a2, a4, and a6 are the second, fourth, and sixth order coefficients of the first region 112, respectively;

[0052] c' is the base curvature of the second zone 114;

[0053] k' is the cone constant of the second region 114; and

[0054] a2′, a4′, and a6 are the second, fourth, and sixth order coefficients of the second region 114, respectively;

[0055] Δ1 is the step height of the phase shift feature 120 relative to the inner region 116; and

[0056] Δ2 is the step height of the phase shift feature 120 relative to the outer region 118 .

[0057] Although the base profiles defined above in equation (6) include only second, fourth, and sixth order coefficients, the present disclosure contemplates that those base profiles may alternatively be defined to include any suitable number of higher order coefficients (as in equation (1)).

[0058] Because the first region 112 and the second region 114 have different base concave profiles, Δ3 (as defined in Equation (8)) can provide a smooth transition between the first region 112 and the second region 114. For example, the first region 112 can be modified to have a different base curvature (c), conic constant (k), and / or higher order coefficients (a2, a4, a6) than the second region 114 to provide a smooth transition between the first region 112 and the second region 114. Figure 3 Compared with the defocus curve depicted in , the defocus curve is shifted toward the myopia direction. Figure 4 A graph of surface concavity versus radial distance from the optical axis is shown for an optical device 102 having a surface profile defined by equations (5)-(8) according to certain embodiments of the present disclosure. Figure 4 The surface profile plotted in takes the following values:

[0059] Table 1

[0060]

[0061]

[0062] The values ​​listed in Table 1 are provided for exemplary purposes only and the present disclosure contemplates that each of these values ​​may have a range of different values. As an example, the present disclosure contemplates that r1 may fall within the range of 0.3 mm to 0.7 mm, r4 may fall within the range of 0.8 mm to 1.2 mm, the distance between r1 and r2 may fall within the range of 0 mm to 0.2 mm, and the distance between r3 and r4 may fall within the range of 0 mm to 0.2 mm. As an additional example, the present disclosure contemplates that Δ1 may fall within the range of -1.5 μm to -0.5 μm, and Δ2 may fall within the range of 0.3 μm to 0.9 μm.

[0063] Figure 5 Certain embodiments of the present disclosure are shown Figure 2 The defocus diagram of the optics depicted in Figure 4; as discussed above, modifying the first zone 112 to a different base curvature, conic constant, and / or higher order coefficients (1) rebalances the energy between mid-distance correction and far correction, and (2) shifts the through focus curve toward the myopia direction (near target direction) compared to the through focus curve of an optical device having the same base curvature in the first zone 112 and the second zone 114.

[0064] Various techniques and materials can be used to manufacture the above-mentioned IOL 100. For example, the optics 102 of the IOL 100 can be formed by various biocompatible polymer materials. Some suitable biocompatible materials include but are not limited to soft acrylic polymers, hydrogels, polymethacrylates, polysulfones, polystyrene, cellulose, acetate butyrate or other biocompatible materials. By way of example, in one embodiment, the optics 102 can be formed by a soft acrylic polymer (a cross-linked copolymer of 2-phenylethyl acrylate and 2-phenylethyl methacrylate) commonly referred to as an artificial lens (Acrysof). The haptic 104 of the IOL 100 can also be formed by suitable biocompatible materials, such as those discussed above. Although in some cases, the optics 102 and haptic 104 of the IOL can be manufactured as an integrated unit, in some cases, they can be formed separately or connected together using techniques known in the art.

[0065] It will be appreciated that various of the above disclosed and other features and functions, and alternatives thereto, may be desirably combined into many other different systems or applications. It will also be appreciated that various currently unseen or unanticipated alternatives, modifications, changes or improvements therein may be subsequently made by those skilled in the art, which alternatives, modifications, changes or improvements are also intended to be covered by the following claims.

Claims

1. An ophthalmic lens comprising: an optical device comprising an optical axis and an optical profile extending radially from the optical axis, the optical profile having a first zone, a second zone, and a phase shifting feature within the first zone, wherein the first zone extends from the optical axis to a first radial boundary, the first zone comprises an inner region and an outer region, the second zone extends from the first radial boundary to an edge of the optical device, the phase shifting feature separating the inner region from the outer region; wherein the phase shifting feature comprises a first phase shifting step, a second phase shifting step, and a ridge of increased thickness extending from the first phase shifting step to the second phase shifting step, and wherein the phase shifting feature is configured to produce a varying amount of phase shifting of a light wave passing through the optical device to provide an extended depth of focus.

2. The ophthalmic lens of claim 1, wherein: The first phase shift step has a first step height; The second phase shift step has a second step height; and The second step height is greater than the first step height, such that the inner region is recessed relative to the outer region.

3. The ophthalmic lens of claim 1, wherein the first zone and the second zone have different aspheric profiles.

4. An ophthalmic lens having an optical axis, the ophthalmic lens comprising a lens element, the lens element comprising: a first zone extending from the optical axis to a first radial boundary, the first zone comprising an inner region and an outer region, and the first zone having a first base curvature; as well as a second zone extending from the first radial boundary toward an edge of the optic and having a second base curvature; The surface profile of the first zone is defined as follows: WITH 第一区 =Z 基础 +Z 2ps in: r is the radial distance from the optical axis; c is the base curvature of the first zone; k is the cone constant; and a2, a4, a6 are the second, fourth, and sixth order coefficients respectively; and in: r0 is the optical axis; The inner region extends from the optical axis to r1; The phase shift feature extends from r1 to r4; The outer region of the first zone extends from r4 to r5; Δ1 is the step height of the phase shift feature relative to the inner region; and Δ2 is the step height of the phase shift feature relative to the outer region, wherein the phase shifting features are configured to produce different amounts of phase shifts in light waves passing through the optical device, and Wherein the first base curvature of the first zone is configured to provide an increased focusing range in a near vision direction.

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