Electro-active lens with cylindrical rotation control

Abstract

An electroactive lens having stacked rotating cylindrical electroactive lens elements can provide cylindrical refractive power along more axes than the cylindrical electroactive lens elements themselves. For example, six stacked cylindrical electroactive lens elements (each aligned with a different lens meridian) can produce cylindrical refractive power along fifteen distinct meridians when actuated by a maximum of three at a time. If these fifteen meridians are arranged at 12° increments, the lens stack can provide well-aligned cylindrical refractive power to correct astigmatism along any axis. Each cylindrical electroactive lens element in the stack may include a liquid crystal layer actuated by linear electrodes parallel to each other and orthogonal to both the cylindrical axis and the optical axis of the cylindrical electroactive lens element. The electroactive lens may also include spherical lens elements that provide spherical refractive power in addition to any net spherical refractive power produced by the stacked cylindrical electroactive lens elements.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Application No. 63 / 070,858, filed August 27, 2020, pursuant to 35U.SC119(e), which is incorporated herein by reference in its entirety. Background Technology

[0003] A patient's corrective lens prescription is typically measured by a healthcare practitioner who records and reports the prescription in terms of sphere (SPH), cylinder (CYL), and axis. The sphere indicates the amount of refractive power of the lens prescribed to correct myopia or hyperopia, usually measured in diopters (D). The cylinder indicates the amount of refractive power of the lens required to correct astigmatism, which occurs when the eye (cornea) or the anterior surface of the lens is oval rather than spherical. Astigmatism can cause blurred vision at all distances. The axis describes the lens meridian that does not contain the cylindrical refractive power used to correct astigmatism. In other words, the axis refers to the rotational orientation of the cylinder error. While the sphere can change rapidly over time, the cylinder and axis rarely change or change very slowly (e.g., over several years), and sometimes never change throughout a patient's lifetime. Lenses that provide both spherical and cylindrical correction are called compound lenses or toric lenses.

[0004] Figure 1A –1E illustrates how an optical cross or refractive power cross can be used to demonstrate a prescription for a lens with cylindrical refractive power. An optical cross is a graphic device used to illustrate the cylindrical refractive power of the front and rear surfaces of a lens. It shows the cylindrical refractive power along the meridians of the lens surface. (The meridians are orthogonal to the optical axis of the lens; the principal meridians are the meridians with the greatest and least refractive power.) For spherical lenses, these refractive powers are the same for each meridian. A cylindrical lens has an optical refractive power of zero along a meridian aligned with the longitudinal axis or refractive power axis of the cylindrical lens. Compound lenses or toric lenses have optical refractive powers that vary with the meridian angle.

[0005] Figure 1A An optical crosshair is shown for a cylindrical lens 100a having a flat rear surface and a convex front surface. This cylindrical lens 100a provides +4.00 diopters (D) of optical refractive power along the 180° meridian (equivalent to the 0° meridian) and provides no optical refractive power along the 90° meridian (equivalent to the 270° meridian). Similarly, Figure 1B It shows relative to Figure 1A The cylindrical lens 100a is rotated 90° to the optical crosshair of the cylindrical lens 100b, which has a flat rear surface and a convex front surface. This rotation causes the optical crosshair to rotate 90°: in Figure 1BIn the center, the optical cross displays an optical refractive power of +4.00 diopters (D) along the 90° meridian and does not display an optical refractive power along the 180° meridian.

[0006] Typically, cylindrical lenses provide optical refractive power along a meridian orthogonal to both their longitudinal axis and optical axis. This meridian need not be 90° or 180°. Figure 1C For example, cylindrical lens 100c is a plano-convex cylinder oriented along a 45° meridian with its longitudinal axis. Its refractive power along its principal meridians is +4.00D (135°) and 0D (0°). Its optical refractive power along the 90° and 180° meridians is +2.00D. This variation of optical refractive power with the meridian angle can be expressed as… Where F cy1 It is the refractive power of a cylinder, and It is the angle between the axis of the cylinder and the new meridian. Figure 1D It shows Figure 1B The cylindrical lens 100b has optical refractive power marked at the 30°, 45°, 60° and 90° meridians (representing 25%, 50%, 75% and 100% cylindrical refractive power, respectively).

[0007] Figure 1E The optical cross of a toric lens is shown, which provides -2.00D of spherical refractive power and +4.00D of cylindrical refractive power along the 45° meridian. The optical refractive power of a toric lens along any meridian is the sum of its spherical and cylindrical refractive powers along that meridian. Its principal meridians are 45° (+2.00D) and 135° (-2.00D). It provides no optical refractive power along the 90° and 180° meridians (the flat ones). Summary of the Invention

[0008] Electroactive (EA) lenses (such as liquid crystal lenses) can produce a wide variety of optical wavefront shapes, making them ideal candidates for correcting refractive errors in human vision. Although EA lenses can produce cylindrical optical refractive power, they are not widely used to correct human astigmatism (which is a cylindrical refractive power error) due to the different rotational orientation of the astigmatic error, and it is not practical to change the rotational orientation of a cylindrical EA lens without using moving mechanical parts.

[0009] This technology allows EA lenses to produce cylindrical refractive power at various axes without the need for moving parts. This type of EA lens comprises a plurality of EA lens elements arranged optically in series. Some of these EA lens elements are referred to as cylindrical EA lens elements or cylindrical lens elements, and have linear electrodes orthogonal to the optical axis of the EA lens and rotating about the optical axis relative to the linear electrodes of the other cylindrical EA lens elements in the EA lens. The orientation or direction of the linear electrodes in each of these cylindrical EA lens elements defines the axis of the cylinder produced by that cylindrical EA lens element. One or more other EA lens elements in the EA lens provide spherical correction. This allows the EA lens to adequately correct for the sphere, cylinder, and axis in virtually any eyeglass or contact lens prescription.

[0010] An exemplary electroactive lens may include three electroactive elements optically connected in series. A first electroactive lens element provides a first variable cylindrical refractive power in a first meridian of the electroactive lens. A second electroactive lens element provides a second variable cylindrical refractive power in a second meridian of the electroactive lens, different from the first meridian. And a third electroactive lens element provides a third variable cylindrical refractive power in a third meridian of the electroactive lens, different from the first and second meridians. The second meridian can be rotated relative to the first meridian about the optical axis of the electroactive lens by an angle of up to about 24°. Similarly, the third meridian can be rotated relative to the first meridian about the optical axis of the electroactive lens by an angle of less than 90°.

[0011] A first electroactive lens element may include a first liquid crystal layer and a first array of linear electrodes, the linear electrodes being perpendicular to the first meridian and the optical axis of the electroactive lens and configured to actuate the first liquid crystal layer. Similarly, a second electroactive lens element may include a second liquid crystal layer and a second array of linear electrodes, the linear electrodes being perpendicular to the second meridian and the optical axis of the electroactive lens and configured to actuate the second liquid crystal layer. And a third electroactive lens element may include a third liquid crystal layer and a third array of linear electrodes, the linear electrodes being perpendicular to the third meridian and the optical axis of the electroactive lens and configured to actuate the third liquid crystal layer.

[0012] The electroactive lens may also include a fourth electroactive lens element optically connected in series with the first, second, and third electroactive lens elements. In operation, the fourth electroactive lens element provides a fourth variable cylindrical refractive power in a fourth meridian of the electroactive lens, which is different from the first, second, and third meridians.

[0013] Alternative electroactive lenses may include cylindrical electroactive lens elements arranged optically in series with each other and with at least one other electroactive lens element. The cylindrical electroactive lens element may provide cylindrical optical refractive power at different corresponding axes relative to the optical axis of the electroactive lens. Furthermore, another electroactive element may provide variable spherical optical refractive power, which may be selected to offset the spherical refractive power provided by two or more cylindrical electroactive lens elements.

[0014] Cylindrical electroactive lens elements may include corresponding bistable electroactive material layers. There may be three, four, five, or six cylindrical electroactive lens elements. If there are six cylindrical electroactive lens elements, these elements can be aligned to provide cylindrical refractive power at meridians of 0, 24, 72, 120, 144, and 168 degrees, respectively. Each cylindrical electroactive lens element can be actuated independently.

[0015] Each cylindrical electroactive lens element may include a liquid crystal material layer and an array of linear electrodes. The linear electrodes are electrically connected to the liquid crystal material layer and are perpendicular to the optical axis of the electroactive lens. They can apply an electric field to the liquid crystal material layer, thereby enabling the liquid crystal material layer to provide a variable cylindrical optical refractive power orthogonal to the optical axis of the electroactive lens.

[0016] Cylindrical rotation control can be achieved using an electroactive lens comprising a stack of cylindrical electroactive lens elements configured to provide cylindrical optical refractive power at corresponding axes relative to the optical axis of the electroactive lens. The process includes: providing cylindrical refractive power along a first meridian using a first cylindrical electroactive lens element in the stack; and simultaneously providing cylindrical refractive power along the first meridian using a second cylindrical electroactive lens element in the stack along a second meridian within 60 degrees of the first meridian.

[0017] The first meridian can be within 24 degrees of the second meridian. The cylindrical refractive power along the first and second meridians can be added together to produce the cylindrical refractive power along the meridian midway between the first and second meridians. For a person viewing through an electroactive lens, the meridian midway between the first and second meridians can be within 6 degrees of cylinder correction.

[0018] While providing cylindrical refractive power along the first and second meridians using a first cylindrical electroactive lens element and a second cylindrical electroactive lens element respectively, a third cylindrical electroactive lens element in the stack of cylindrical electroactive lens elements provides cylindrical refractive power along a third meridian different from the first and second meridians. Similarly, one or more lens elements optically connected in series with the stack of cylindrical electroactive lens elements can provide spherical optical refractive power. This spherical optical refractive power can be selected based on the spherical optical refractive power generated by the combination of the first and second cylindrical electroactive lens elements.

[0019] All combinations of the foregoing concepts and the additional concepts discussed in more detail below (provided that these concepts do not contradict each other) are contemplated as part of the inventive subject matter disclosed herein. In particular, all combinations of the claimed subject matter appearing at the end of this disclosure are considered part of the inventive subject matter disclosed herein. Terms expressly used herein, which may also appear in any disclosure incorporated by reference, shall be given the meaning most consistent with the specific concepts disclosed herein. Attached Figure Description

[0020] Those skilled in the art will understand that the accompanying drawings are primarily for illustrative purposes and are not intended to limit the scope of the inventive subject matter described herein. The drawings are not necessarily drawn to scale; in some cases, various aspects of the inventive subject matter disclosed herein may be exaggerated or enlarged in the drawings to aid in understanding different features. In the drawings, similar reference numerals generally refer to similar features (e.g., functionally and / or structurally similar elements).

[0021] Figure 1A A vertically oriented cylindrical lens superimposed on a corresponding optical cross is shown.

[0022] Figure 1B A horizontally oriented cylindrical lens is shown superimposed on a corresponding optical cross.

[0023] Figure 1C A cylindrical lens with diagonal orientation superimposed on a corresponding optical cross is shown.

[0024] Figure 1D A cylindrical lens with diagonal orientation superimposed on a corresponding optical cross is shown.

[0025] Figure 1E The optical cross of a toric lens is shown.

[0026] Figure 2A A cylindrical electroactive lens element (top) and a plano-concave cylindrical lens (bottom) are shown.

[0027] Figure 2BIt shows a rotation of approximately 45° around the optical axis. Figure 2B A cylindrical electroactive lens element.

[0028] Figure 3A An electroactive lens is shown, comprising a group of rotating cylindrical electroactive lens elements arranged in optical series with each other and with spherical cylindrical electroactive lens elements.

[0029] Figure 3B It shows Figure 3A The optical cross of the electroactive lens consists of the third cylindrical electroactive element (left), the fourth cylindrical electroactive element (middle), and two cylindrical electroactive elements together (right).

[0030] Figure 3C For optical refractive power Figure 3A A diagram showing the changes in the meridian angles of the third cylindrical electroactive element, the fourth cylindrical electroactive element, the two cylindrical electroactive elements together, and the two cylindrical electroactive elements together that remove or deflect the spherical refractive force of the electroactive lens.

[0031] Figure 4 This is a graph showing the logarithm of the minimum resolvable angle (LogMAR) measured on a visual acuity chart and the misalignment of the cylinder axes of four different cylindrical refractive powers.

[0032] Figure 5 Different possible meridian angles are shown for stacked cylindrical electroactive lens elements (layers) used in electroactive lenses.

[0033] Figure 6 This is a diagram showing the 22 different cylindrical axis possibilities when using a combination of three cylindrical lenses from six available cylindrical lenses.

[0034] Figure 7 This is a graph of the cylinder axis in degrees relative to a group of 4,000 Americans with astigmatism.

[0035] Figure 8 An electroactive spectacle lens with stacked cylindrical electroactive lens elements for cylinder rotation control is shown.

[0036] Figure 9 An electroactive contact lens with stacked cylindrical electroactive lens elements for cylinder rotation control is shown.

[0037] Figure 10 An electroactive contact lens with stacked cylindrical electroactive lens elements for cylinder rotation control is shown. Detailed Implementation

[0038] Figure 2A and 2BAn exemplary electroactive cylindrical lens element 200, also known as a cylindrical or cylindrical electroactive lens element, is shown, which can be used to provide variable cylindrical optical refractive power. This electroactive cylindrical lens element 200 includes a single layer of electroactive material (e.g., bistable liquid crystal material) sandwiched between a pair of transparent substrates (e.g., made of glass or polymer). One substrate is coated with a ground plane electrode, and the other substrate is coated with an array of parallel linear electrodes 205a–205n. When no voltage is applied to the electrodes 205, an alignment layer (not shown) on the electrode 205 layer aligns the liquid crystal material relative to the substrate and the electrodes. The leftmost electrode 205a and the rightmost electrode 205n in the parallel linear electrode array are labeled in Figure 1.

[0039] Linear electrode 205 is coupled to and controlled by electrode control circuit 207, which may be located at one edge of the electroactive cylindrical lens element 200. Each electrode 205 may have its own electrode control circuit 207, or the electrodes 205 may share the same electrode control circuit 207. In the case of shared circuitry, there should be at least sufficient control circuitry 207 to generate cylindrical optical refractive power.

[0040] In operation, electrode control circuit 207 applies voltage to some or all of the linear electrodes 205. These voltages actuate the electroactive material, thereby altering the optical refractive power of the lens along a 180° meridian, i.e., in a direction orthogonal to the optical axis of the electrode 205 and the lens, said direction being orthogonal to the plane of the substrate and the electroactive material. Electrode control circuit 207 can apply different voltages to each electrode 205 to produce a cylindrical optical refractive power that mimics the optical refractive power of a conventional plano-concave cylindrical lens 15. Plotting the voltage relative to the number of electrodes produces parabolic arcs, circular arcs, or phase-wound arcs that mimic the shape of the concave side of the plano-concave cylindrical lens 15. For example, zero volts can be applied to the center electrode, 0.5 volts can be applied to the adjacent electrodes on either side of the center electrode, and the next electrode adjacent to them has a slightly higher voltage; this pattern of increasing voltage applied to the electrodes is repeated multiple times as the distance between these electrodes and the center electrode increases.

[0041] Changing the shape and amplitude of this voltage distribution curve alters the cylindrical optical refractive power provided by lens element 200 along the 180° meridian. Typically, cylindrical lenses are tuned to deliver variable cylindrical refractive power ranging from 0 to ±6.00D or more. Lens element 200 does not provide optical refractive power along the 90° meridian. If desired, lens element 200 can be rotated to provide cylindrical optical refractive power along another meridian. Figure 2B For example, lens element 200 is rotated 45° to provide variable optical refractive power along the 135° meridian, and does not provide optical refractive power along the 45° meridian.

[0042] Figure 3A An electroactive lens 300 is shown, having a plurality of cylindrical electroactive lens elements 200a–200d arranged in optical series with individual spherical electroactive lens elements 310 having concentric circular electrodes 315. In this example, there are four cylindrical electroactive lens elements 200, but other electroactive lenses 300 may have more or fewer cylindrical electroactive lens elements 200, as discussed in more detail below. Similarly, the electroactive lens 300 may include more or fewer (i.e., zero) spherical electroactive lens elements, each of which can provide the same amount of spherical optical refractive power or different amounts of spherical optical refractive power. Instead of or as a supplement to the spherical electroactive lens element with concentric circular electrodes, two orthogonally oriented cylindrical electroactive lens elements may also be used to provide spherical optical refractive power.

[0043] Electroactive lens elements may be embedded in or at least partially encapsulated by a transparent substrate. This substrate may be rigid or flexible and may have the same or substantially the same refractive index as the unactuated electroactive material (e.g., liquid crystal material) in the lens element for fault-protection operation. The substrate may have an out-of-plane surface that does not provide optical refractive power or a bending or diffractive outer surface or refractive index gradient, in order to provide fixed optical refractive power in addition to the variable cylindrical and spherical optical refractive power provided by the electroactive lens element.

[0044] exist Figure 3A In this embodiment, cylindrical electroactive lens elements 200a–200d rotate relative to each other about the optical axis. That is, the cylindrical electroactive lens elements 200a–200d have different principal meridians. The linear electrode 205 of each cylindrical electroactive lens element 200 is aligned with the meridian corresponding to the minimum optical refractive power. In this example, lens elements 200a, 200b, 200c, and 200d rotate about the optical axis such that their linear electrodes are parallel to the 135°, 15°, 105°, and 45° meridians, and provide variable optical refractive power along orthogonal meridians (i.e., the 135°, 15°, 105°, and 45° meridians, respectively).

[0045] As explained above, one or more control circuits 207 apply power to each electrode in the different cylindrical electroactive lens elements 200. The cylindrical electroactive lens elements can be actuated independently of each other, and more than one lens element can be actuated simultaneously. If multiple lens elements are actuated simultaneously, their optical refractive powers are added as described above.

[0046] For example, actuating one of the spherical electroactive lens element 310 and the cylindrical electroactive lens element 200 generates a toric optical refractive power for astigmatism correction, for example, as for... Figure 1EThis is illustrated in a conventional toric lens. However, unlike conventional lenses, the amount of optical refractive power can be adjusted by changing the voltage applied to the electroactive lens element. Furthermore, the refractive power of the cylinder can be rotated about the optical axis (i.e., rotated to different principal meridians) by changing which cylindrical electroactive lens element 200 is actuated, without requiring any moving parts. Figure 3A In the electroactive lens 300, cylindrical electroactive lens elements 200 are aligned along four different axes, such that astigmatism along each of these axes can be corrected by actuating the corresponding cylindrical electroactive lens elements 200. Actuating orthogonally aligned cylindrical electroactive lens elements 200 (e.g., cylindrical electroactive lens elements 200b and 200c) to provide the same cylindrical refractive power produces net spherical refractive power.

[0047] If more than one cylindrical electroactive lens element 200 is simultaneously actuated, their cylindrical refractive forces are added together, thus making the electroactive lens 300 function as a compound lens. Because the cylindrical electroactive lens elements 200 have different principal meridians (i.e., they rotate relative to each other about the optical axis), the principal meridians of the electroactive lenses can be located at intermediate positions. For example, simultaneously actuating two cylindrical electroactive lens elements 200 produces maximum optical refractive force along a meridian that is midway between the meridians of maximum optical refractive force for the two actuated cylindrical electroactive lens elements 200.

[0048] More specifically, cylindrical electroactive lens elements 200c and 200d (with maximum optical refractive power meridians of 105° and 45°, respectively) are actuated to provide the same size cylindrical refractive power along a 75° meridian, producing a net maximum or combined maximum cylindrical refractive power. Similarly, cylindrical electroactive lens elements 200b and 200c (with maximum optical refractive power meridians of 15° and 105°, respectively) are actuated to provide the same size cylindrical refractive power along a 60° meridian, producing a net maximum or combined maximum optical refractive power. Orthogonal cylindrical electroactive lens elements (e.g., elements 200a and 200d) are actuated to provide the same size cylindrical refractive power, producing a net spherical refractive power.

[0049] Figure 3B and 3C Table 1 (hereinafter) shows the individual and net optical refractive powers provided by actuating cylindrical electroactive lens elements 200c and 200d to provide a cylindrical refractive power of +4.00D, respectively. Figure 3BThe optical cross is shown for element 200c (left), element 200d (middle), and two elements in series (right). The maximum optical refractive power of the two elements in series is +6.00D at the 75° meridian, which is midway between the 105° and 45° meridians of maximum optical refractive power for elements 200c and 200d, respectively. The minimum optical refractive power of the two elements in series is +2.00D at the 165° meridian. Figure 3C Table 1 shows the optical refractive power provided at other meridians.

[0050] Two cylindrical electroactive elements 200c and 200d are actuated together, equivalent to a spherical lens element providing +2.00D of optical refractive power, which is connected in series with a cylindrical lens element providing +4.00D of cylindrical refractive power at the 75° axis. If desired, the spherical optical refractive power can be offset by actuating the spherical electroactive lens element 310 to provide -2.00D of spherical refractive power. With both cylindrical electroactive elements 200c and 200d actuated to each provide a maximum cylindrical refractive power of +4.00D and the spherical electroactive lens element 310 actuated to provide -2.00D of spherical refractive power, the electroactive lens 300 provides a net optical refractive power of +4.00D of cylindrical refractive power at the 75° axis. Alternatively, the spherical electroactive lens element 310c can be actuated to provide additional spherical refractive power or to reduce the spherical refractive power.

[0051] Meridian (°) Component 200c Component 200d sum The sphere is relatively small 0 0.27 2.00 2.27 0.27 15 0.00 3.00 3.00 1.00 30 0.27 3.73 4.00 2.00 45 1.00 4.00 5.00 3.00 60 2.00 3.73 5.73 3.73 75 3.00 3.00 6.00 4.00 90 3.73 2.00 5.73 3.73 105 4.00 1.00 5.00 3.00 120 3.73 0.27 4.00 2.00 135 3.00 0.00 3.00 1.00 150 2.00 0.27 2.27 0.27 165 1.00 1.00 2.00 0.00 180 0.27 2.00 2.27 0.27

[0052] Table 1

[0053] Therefore, simultaneously actuating more than one cylindrical electroactive lens element 200 allows the net cylindrical refractive power provided by the electroactive lens 300 to rotate about the optical axis of the electroactive lens 300. The cylindrical electroactive lens element 200 can be dynamically actuated to provide a net cylindrical refractive power whose magnitude and rotation angle vary over time. Simultaneously, the spherical lens element 310 can be dynamically actuated as needed to provide additional spherical refractive power. This spherical refractive power can be added to the net refractive power provided by the electroactive lens or reduced by any spherical refractive power generated by the actuated cylindrical electroactive lens element 200.

[0054] If the cylindrical electroactive lens element 200 is bistable, it can also be actuated or set once and then held in that setting to provide a static or constant net cylindrical refractive power without consuming any electricity. For example, if the cylindrical electroactive lens element 200 comprises a bistable liquid crystal material, applying a suitable voltage to the liquid crystal material will cause it to redirect itself and remain in the redirected position until a subsequent voltage is applied. This liquid crystal redirection alters the refractive index profile and thus changes the cylindrical refractive power provided by the cylindrical electroactive lens element 200. Alternatively, the cylindrical electroactive lens element 200 may comprise an electroactive material, such as liquid crystal in a curable polymer matrix, which can be permanently fixed in place by curing with heat or ultraviolet radiation. Fixing the cylindrical refractive power can be very useful for ophthalmic lenses because astigmatism correction is often the same for myopia and hyperopia correction, which can be dynamically corrected by opening and closing the spherical electroactive lens element 310.

[0055] If the cylindrical electroactive lens elements 200 are configured to provide static cylindrical refractive power, they can also provide static spherical refractive power, such as... Figure 3B and 3C As in the example. This static spherical refractive power can be considered as a biased spherical refractive power, rather than something that can be added to an optional base lens element made of glass or plastic. Figure 3A The static optical refractive power provided (not shown in the image) can also be offset by switching the spherical electroactive lens element 310 between non-zero values ​​(e.g., between positive and negative values ​​or between two different positive or negative values). For example, suppose a person's prescription is +0.50D of cylindrical refractive power for both myopia and hyperopia, and switches between 0.00D of spherical refractive power for hyperopia and +1.50D of spherical refractive power for myopia. If the cylindrical electroactive lens element provides +0.50D of cylindrical refractive power and +0.125D of spherical refractive power, then the spherical electroactive lens element can be set to provide –0.125D of spherical refractive power when closed and +1.375D of spherical refractive power when open, to provide net spherical refractive power of 0.00D and +1.50D, respectively, when closed and open.

[0056] The number and alignment of cylindrical electroactive lens elements

[0057] The number and alignment of cylindrical electroactive lens elements in an electroactive lens with cylinder rotation control depend on the desired degree of cylinder rotation control. For ophthalmic applications, clinical studies have shown that satisfactory visual results are achieved when the cylinder axis is aligned within ±6° of the actual axis of the desired cylinder prescription. For example, Figure 4This graph shows the minimum resolving angle logarithm (LogMAR) measured on a visual acuity chart and its correlation with cylinder axis misalignment at four different cylindrical refractive powers (full cylinder power (solid black line), less than 0.25 cylinder power correction (DC; solid dark gray line), less than 0.5 DC correction (dashed light gray line), and less than 0.75 DC correction (dashed line)). The graph illustrates that for cylinder axis misalignment up to approximately ±10°, the LogMAR differs from the best corrected visual acuity sensitivity (BCVA) by less than 0.1, even for full correction. At cylinder axis misalignment up to approximately ±5°, the LogMAR differs from the BCVA by less than 0.05. This indicates that rotational control of the cylinder axis of the corrective lens does not need to be continuously adjustable; it can be adjusted incrementally in rotational steps of 20°, 12°, 10°, 6°, or less.

[0058] As referenced above Figure 3A One way to provide multi-axis cylindrical rotation in an electroactive lens is to stack several cylindrical electroactive lens elements, each with a different axis of rotation (principal meridian). Then, when a specific axis of rotation is needed, the cylindrical electroactive lens element with that axis is activated, and the other cylindrical electroactive lens elements are deactivated. For example, a lens with 15 layers can provide adjustment in 6° increments or steps.

[0059] Figure 4 Fifteen increments of axial rotation are shown for aligning a cylindrical lens, provided by cylindrical electroactive lens elements, to within 6° of the desired axial correction. These increments / meridians are 0, 12, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, and 180 degrees. Aligning an electroactive lens with fifteen cylindrical electroactive lens elements to provide cylindrical refractive power at these meridians can correct human astigmatism as follows: The astigmatic axis in the eye is in the range of zero to 180°. If as... Figure 4As in the example, fifteen cylindrical electroactive lens elements are arranged at evenly spaced meridians, with an increment of 12° between the meridians of adjacent cylindrical electroactive lens elements. Any desired axis rotation should fall within 6° of the meridian of the maximum optical refractive power of one of these cylindrical electroactive lens elements. For example, if the desired axis correction is 30°, this axis value is located midway (and 6° away) from the cylindrical refractive power provided by two cylindrical electroactive lens elements that can provide cylindrical refractive power along the 24° and 36° meridians. Therefore, any of these cylindrical electroactive lens elements can provide sufficient correction. In another example, the desired axis correction at the 31° meridian is 5° away from the cylindrical electroactive lens element aligned with the 36° meridian. The axis (meridian) of the cylinder can be held in place by the eyeglass frame when used in spectacle lenses, by the capsule when used in IOLs, and by a weight placed at the bottom of the contact lens.

[0060] While it is possible to stack fifteen layers (cylindrical electroactive lens element) in a single electroactive lens, having so many layers of liquid crystal material presents disadvantages. Some of these disadvantages are greater complexity, greater thickness, and greater haze when viewed through an electroactive lens. It may be desirable to reduce the number of layers used while still providing a large number of possible cylindrical correction axes.

[0061] Fortunately, electroactive lenses can produce fifteen different cylindrical rotations using fewer than fifteen layers (cylindrical electroactive lens elements) by actuating more than one layer at a time. For example, if a layer that produces cylindrical refractive power along the 48° meridian is combined with a layer that produces cylindrical refractive power at the 24° meridian, the resulting axis of rotation will be at 36° (midway) between these values. Using this method, the number of layers can be reduced from 15 to 9, for example, with alignments at meridians of 0, 24, 48, 72, 96, 120, 144, 168, and 180 degrees (here, 180 degrees is divided into nine 24-degree increments, including the starting and ending values).

[0062] Table 2 (below) shows the resulting axes when adjacent electrodes are switched on, thus generating fifteen axis combinations using only eight cylindrical electroactive lens elements. Columns titled "Axis 1" and "Axis 2" indicate the rotational orientation (meridian) of the first and second actuated cylindrical electroactive lens elements. In this example, each actuated cylindrical electroactive lens element provides the same amount of cylindrical refractive power. A blank in the "Axis 2" column indicates that only one cylindrical electroactive lens element is actuated. Columns titled "Results" list the rotational axes (meridians) of the actuated cylindrical electroactive lens elements with the maximum net cylindrical refractive power.

[0063]

[0064]

[0065] Table 2

[0066] The first and last layers are redundant (the 0° and 180° meridians coincide), so one of them can be eliminated, leaving eight stacked layers (cylindrical electroactive lens elements). Even with only eight stacked layers, the electroactive lens can still provide astigmatism correction within 6° of alignment. This is achieved by using a zero-degree axis instead of a 180-degree axis, which are optically equivalent. Thus, for example, correction at the 174° meridian is equidistant between the 0° and 168° meridians (where 0° coincides with 180°), with each correction within 6 degrees. This reduces the number of angular increments to 14, which can be achieved with eight layers, such as 0, 24, 48, 72, 96, 120, 144, and 168 degrees.

[0067] Fourteen increments can be achieved using even a small number of layers by activating two different layers that are not necessarily adjacent to each other. For example, Table 3 shows that an electroactive lens with six layers (cylindrical electroactive elements) at the 0, 24, 72, 120, 144, and 168 degree meridians can produce 15 different cylindrical rotations in 12° increments.

[0068] Shaft 1 Axis 2 result 0 none 0 0 24 12 24 none 24 0 72 36 24 72 48 0 120 60 72 none 72 24 144 84 24 168 96 72 144 108 120 none 120 120 144 132 168 120 144 168 144 156 168 none 168

[0069] Table 3

[0070] A finer level of resolution can be achieved by simultaneously actuating three layers instead of just two. For example, Table 4 shows the cylindrical rotation meridians achievable by stacking six cylindrical electroactive lens elements aligned with the 0, 24, 72, 120, 144, and 168 degree meridians. Actuating three of these lens elements at a time produces twenty-two possible unique cylindrical axis rotations, with the centrally distributed rotations offering the finest resolution. (The unique cylindrical axis rotations are shown on the right side of Table 4.)

[0071] Figure 6 This is a diagram of the 22 different cylindrical axis possibilities when selecting and opening only three lenses from a product portfolio of six different oriented lenses, as described in Tables 3 and 4 above.

[0072]

[0073] Table 4

[0074] Figure 7This is a graph showing the distribution of cylindrical meridians in a US population of 4,000 people with astigmatism. The vertical axis shows the cylindrical meridians, and the horizontal axis shows the population count. This indicates that the cylindrical meridian distribution is not uniform: instead, about half of the population (2,000 people) have cylindrical meridians between approximately 80° and 100°. Another 2,000 or so people in the population have cylindrical meridians falling between 0° and 80° or between 100° and 180°. This distribution suggests that cylindrical correction can be provided for most of the astigmatic population using electroactive lenses with fewer than six stacked layers (cylindrical electroactive lens elements). Alternatively, the layers of the electroactive lens can be rotated to provide finer resolution between 80° and 100° (i.e., correction within less than 6° of the desired cylindrical meridian).

[0075] For example, an electroactive lens with fewer layers can produce some, but not all, of the desired increments to meet the cylindrical axis possibilities for each patient. For instance, an electroactive lens with four layers can produce fourteen unique cylindrical axis combinations, but these combinations may not span 180 degrees in 12-degree increments. However, such a lens can be configured as a stock unit (SKU) #1 for patients with cylindrical axes falling within the 0° to 84° range, while a second SKU #2 with four layers at different meridians can be configured for patients with cylindrical axes falling within the 96° to 180° range. The disadvantage of this approach is the need for two SKUs, but the advantage is that each SKU has only four layers instead of six, and it can be simpler, thinner, lighter, and more transparent (i.e., less hazy). This approach can be further developed to increase the number of SKUs to further reduce the number of layers per SKU as needed.

[0076] Tables 5 and 6 (below) illustrate the possible design parameters for SKU#1 and SKU#2. Each SKU has four layers (cylindrical electroactive lenticule elements) AD, which are oriented to provide cylindrical refractive power along different axes (meridians). Actuating one, two, or three layers in each SKU produces a net cylindrical refractive power across the desired range. These parameters can be adjusted as needed. The layers can be set or fixed in place according to the patient's prescription as described above. The SKU may also include static or dynamic spherical lenticule elements to provide additional spherical refractive power or offset the spherical refractive power provided by the layers.

[0077]

[0078]

[0079] The examples above illustrate the concept and are not intended to be a comprehensive list of all possible combinations. Those skilled in the art can calculate other combinations that may include fewer or more layers and finer or coarser axis separation increments, or even not covering the entire 180 degrees but clustering into a narrower group to achieve a finer level of resolution within that group of axes.

[0080] Eyeglasses, contact lenses, and artificial lenses with cylinder rotation control

[0081] Figure 8 Eyeglasses or goggles 800 with electroactive lenses 810 having cylindrical rotation control are shown. The electroactive lenses 810 are held in place by a front frame portion 820, which is connected to the left and right temples 830 via corresponding (optional) hinges. The front frame portion 820, temples 830, and optional hinges together form the frame of the eyeglasses 800. Each lens 810 contains at least three, and possibly more, stacked cylindrical electroactive lens elements (layers) 812. These layers 812 are actuated by linear electrodes, similar to... Figure 3A The electroactive lens 300 is shown. Each lens 810 may also include a dynamic spherical lens element stacked with layer 812. And the lens 810 itself may have a curved outer surface to provide additional spherical or cylindrical refractive power.

[0082] As explained above, the cylindrical electroactive layers 812 in each lens 810 rotate relative to each other about the optical axis of the lens to provide rotational control over the adjustable / dynamic cylinder correction provided by the lens 810. This rotational control can be provided by a switch on the eyeglasses 800 or by a remote control (e.g., a smartphone with a suitable app) wirelessly coupled to the electronics 814 in response to sensor readings or user input. Alternatively, the rotational control can be fixed, for example, by an optician who determines the patient's prescription and fits the eyeglasses to the patient.

[0083] In this case, for example, each set of electroactive layers 812 is sealed or formed within a glass or plastic substrate lens element using 3D printing or other additive manufacturing techniques. The substrate lens element can provide a fixed optical refractive power from –30 diopters to +30 diopters. For some applications, such as augmented or virtual reality applications, the substrate lens element may not provide any optical refractive power (i.e., it may have 0 diopters of optical refractive power).

[0084] The electroactive layer 812 is powered and controlled by electronic device 814, which can be embedded in the periphery of the substrate lens element, out of the wearer's line of sight, such as... Figure 8As shown in the diagram. Some or all of these electronic devices may also be embedded or housed in the front of the frame 820 or the temple 830, wherein there is a wired or radio connection between the electronic devices and the power source. These electrical connections may take the form of conductive traces or wires extending through or across (optionally) the hinges and base lens elements. They may also take the form of conductive rings that wirelessly couple energy from the power source to layer 812 and / or electronic devices 814.

[0085] Because the electroactive layer 812 provides cylindrical rotational control, the lens 810 can be fitted into the front portion 820 of the frame without regard to its alignment. This makes it easier to shape the lens 810 using edging techniques or 3D printing and align the lens 810 with the front portion 820 of the frame—rotational alignment of the lens 810 relative to the front portion 820 of the frame is not required unless the base lens element provides a fixed rotational refractive power or correction. Instead, the lens 810 can be inserted into the front portion 820 of the frame in any rotational orientation, and the cylindrical refractive power can be adjusted (once or repeatedly if needed) by actuating the layer 812 with control electronics 814.

[0086] Figure 9 An electroactive contact lens 900 providing cylinder rotation control is shown. (Compared to...) Figure 8 Similar to spectacle lens 810, electroactive contact lens 900 includes stacked electroactive layers 912 embedded or fixed to the substrate optic element 910. Each electroactive layer 912 has its own parallel linear electrode rotated at a different angle relative to the optical axis of the contact lens and provides cylindrical refractive power along different meridians (e.g., like...). Figure 3A (As in the stacked electroactive layer 200). The substrate optics 910 can provide a fixed optical refractive power from -30 diopters to +30 diopters (including 0 diopters) and is made of a biocompatible material, such as soft, permeable acrylic or other materials suitable for use in contact lenses. The substrate optics 910 also encapsulates electronics 914 and a power source, such as a capacitor or battery, which powers the electronics 914 and layer 912. The electronics 914 and the power source can be made of transparent or translucent materials and / or positioned outside the user's line of sight.

[0087] Electronic device 914 may include a sensor that detects or measures the rotational orientation of the contact lens relative to a desired cylindrical rotation angle. Electronic device 914 uses this information to actuate layer 914 to provide the desired cylindrical refractive power. Alternatively, electronic device 914 may include an antenna or other wireless interface, in which case electronic device 914 can actuate layer 914 in response to a wireless command from a remote control operated by the wearer or optician.

[0088] Figure 10An electroactive intraocular lens (IOL) 1000 with cylinder rotation control is shown. Similar to... Figure 9 The electroactive contact lens 900, or electroactive IOL 1000, includes a tactile element 1020 extending from a base lens element 1010, which hermetically encapsulates a stacked rotating electroactive layer 1012 with linear electrodes, electronics 1014, and a power source. The base lens element 1010 can also provide a fixed optical refractive power from -30 diopters to +30 diopters. The IOL 1000 can be flexible, allowing it to be rolled or folded and then inserted into the eye via a small incision. Once inside the eye, the IOL 1000 unfolds, and the tactile element 1020 anchors the IOL 1000 in place. Unfortunately, the rotational orientation of the anchored IOL 1000 may not match the desired axis of rotation. Fortunately, the electronics 1014 can actuate the EA layer 1012 to provide any of the cylindrical correction ranges described above to compensate for this misalignment. Precise cylindrical correction can be set by the patient or surgeon via remote control or using a sensor inside or coupled to the IOL 800 that measures the patient’s astigmatism.

[0089] Conclusion

[0090] Although various embodiments of the invention have been described and illustrated herein, those skilled in the art will readily conceive of a variety of other means and / or structures for performing functions and / or obtaining results and / or one or more advantages described herein, and each of such variations and / or modifications is considered to be within the scope of the embodiments of the invention described herein. More generally, those skilled in the art will readily understand that all parameters, dimensions, materials, and configurations described herein are exemplary, and actual parameters, dimensions, materials, and / or configurations will depend on one or more specific applications for which the invention is taught. Those skilled in the art can recognize or determine many equivalents of the particular inventive embodiments described herein using at most conventional experimentation. Therefore, it should be understood that the foregoing embodiments are presented by way of example only, and that the inventive embodiments can be practiced in ways other than those specifically described and claimed within the scope of the appended claims and their equivalents. The inventive embodiments of this disclosure relate to each individual feature, system, article, material, kit, and / or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and / or methods (if such features, systems, articles, materials, kits, and / or methods are not inconsistent with each other) is included within the inventive scope of this disclosure.

[0091] Furthermore, various inventive concepts can be embodied in one or more methods, examples of which have been provided. Actions performed as part of a method can be ordered in any suitable manner. Therefore, embodiments can be constructed that perform actions in an order different from that described, which may include the simultaneous execution of some actions, even those shown as sequential in the illustrative embodiments.

[0092] It should be understood that all definitions defined and used herein take precedence over dictionary definitions, definitions in referenced documents, and / or the general meaning of the terms used in the definitions.

[0093] As used herein in the specification and claims, the indefinite article “a” should be understood to mean “at least one” unless explicitly indicated to the contrary.

[0094] As used herein in the specification and claims, the phrase “and / or” should be understood to mean “any one or two” of the elements so combined, that is, the elements exist together in some cases and separately in others. Multiple elements listed with “and / or” should be interpreted in the same way, that is, “one or more” of the elements so combined. In addition to the elements specifically indicated by the “and / or” clause, other elements may optionally be present, whether related to or unrelated to those specifically indicated. Thus, as a non-limiting example, when used in conjunction with open-ended language (e.g., “comprising”), reference to “A and / or B” may in one embodiment refer only to A (optionally including elements other than B); in another embodiment only to B (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); and so on.

[0095] As used herein in this specification and claims, “or” should be understood to have the same meaning as “and / or” as defined above. For example, when multiple items are separated in a list, “or” or “and / or” should be interpreted as inclusive, that is, including at least one, but also including multiple elements or more than one element in a list of elements and optionally additional unlisted items. Only terms that explicitly indicate the opposite, such as “only one of…” or “exactly one of…” or “consisting of…” when used in claims, will refer to including multiple elements or exactly one element in a list of elements. Generally, the term “or” as used herein should only be interpreted as indicating an exclusive alternative (i.e., “one or the other, but not both”) before exclusive terms such as “any one,” “one,” “only one,” or “exactly one”. “Substantially consisting of…” when used in claims should have the ordinary meaning as it is used in the field of patent law.

[0096] As used herein in the specification and claims, when referring to a list of one or more elements, the phrase "at least one" should be understood to mean at least one element selected from any one or more elements in the list of elements, but not necessarily including at least one of each element specifically listed in the list of elements, and does not exclude any combination of elements in the list of elements. This definition also allows for the optional presence of elements other than those specifically identified in the list of elements referred to by the phrase "at least one," regardless of whether they are related to those specifically identified elements. Thus, as a non-limiting example, in one embodiment, "at least one of A and B" (or, equivalently, "at least one of A or B," or equivalently, "at least one of A and / or B") may refer to at least one, optionally including more than one A, without B (and optionally including elements other than B); in another embodiment, it may refer to at least one, optionally including more than one B, without A (and optionally including elements other than A); in yet another embodiment, it may refer to at least one, optionally including more than one A, and at least one, optionally including more than one B (and optionally including other elements); etc.

[0097] In the claims and in the foregoing description, all conjunctions such as “comprising,” “including,” “with,” “having,” “containing,” “involving,” “accommodating,” and “consisting of” should be understood as open-ended, meaning that they include but are not limited to. As described in Section 2111.03 of the U.S. Patent Examination Procedure Manual, only the transitional phrases “consisting of” and “substantially consisting of” should be closed or semi-closed transitional phrases, respectively.

Claims

1. A method of operating an electroactive lens, the electroactive lens comprising a stack of cylindrical electroactive lens elements and configured to provide cylindrical optical refractive power at different corresponding axes relative to the optical axis of the electroactive lens, the method comprising: The first cylindrical electroactive lens element in the stack of the cylindrical electroactive lens elements provides cylindrical refractive power along the first meridian; While the first cylindrical electroactive lens element provides cylindrical refractive power along the first meridian, a second cylindrical electroactive lens element in the stack of the cylindrical electroactive lens elements provides cylindrical refractive power along a second meridian within 60 degrees of the first meridian. The cylindrical refractive power along the first meridian and the cylindrical refractive power along the second meridian are added together to produce the cylindrical refractive power along the meridian midway between the first meridian and the second meridian.

2. The method according to claim 1, wherein, The first meridian lies within 24 degrees of the second meridian.

3. The method according to claim 1, wherein, For a person viewing through the electroactive lens, the meridian midway between the first and second meridians is within 6 degrees of the cylinder correction.

4. The method according to claim 1, further comprising: While the first cylindrical electroactive lens element provides cylindrical refractive power along the first meridian and the second cylindrical electroactive lens element provides cylindrical refractive power along the second meridian, a third cylindrical electroactive lens element in the stack of the cylindrical electroactive lens elements provides cylindrical refractive power along a third meridian different from the first and second meridians.

5. The method according to claim 1, further comprising: While providing cylindrical refractive power along the first meridian using the first cylindrical electroactive lens element and providing cylindrical refractive power along the second meridian using the second cylindrical electroactive lens element, spherical optical refractive power is provided using at least one lens element optically connected in series with the stack of the cylindrical electroactive lens elements.

6. The method according to claim 5, further comprising: The spherical optical refractive power provided by the at least one element is selected based on the spherical optical refractive power generated by the combination of the first cylindrical electroactive lens element and the second cylindrical electroactive lens element.

7. An electroactive lens, comprising: A stack of cylindrical electroactive lens elements configured to provide cylindrical optical refractive power at different corresponding axes relative to the optical axis of the electroactive lens, the stack of cylindrical electroactive lens elements comprising: A first cylindrical electroactive lens element is used to provide cylindrical refractive power along a first meridian; and The second cylindrical electroactive lens element is used to provide cylindrical refractive power along a second meridian within 60 degrees of the first meridian, while the first cylindrical electroactive lens element provides cylindrical refractive power along the first meridian. The cylindrical refractive power along the first meridian and the cylindrical refractive power along the second meridian are added together to produce the cylindrical refractive power along the meridian midway between the first meridian and the second meridian.

8. The electroactive lens according to claim 7, wherein, The first meridian lies within 24 degrees of the second meridian.

9. The electroactive lens according to claim 7, wherein, For a person viewing through the electroactive lens, the meridian midway between the first and second meridians is within 6 degrees of the cylinder correction.

10. The electroactive lens according to claim 7, wherein, The stack of the cylindrical electroactive lens elements also includes: A third cylindrical electroactive lens element is used to provide cylindrical refractive power along a third meridian different from the first and second meridians, while the first cylindrical electroactive lens element provides cylindrical refractive power along the first meridian and the second cylindrical electroactive lens element provides cylindrical refractive power along the second meridian.

11. The electroactive lens according to claim 7, further comprising: At least one lens element optically connected in series with the stack of the cylindrical electroactive lens elements is used to provide spherical optical refractive power while the first cylindrical electroactive lens element provides cylindrical refractive power along the first meridian and the second cylindrical electroactive lens element provides cylindrical refractive power along the second meridian.

12. The electroactive lens according to claim 11, wherein, The spherical optical refractive power is selected based on the spherical optical refractive power generated by the combination of the first cylindrical electroactive lens element and the second cylindrical electroactive lens element.

13. The electroactive lens according to claim 7, wherein, The cylindrical electroactive lens elements in the stack of the cylindrical electroactive lens elements include corresponding bistable electroactive material layers.

14. The electroactive lens according to claim 7, wherein, The stack of cylindrical electroactive lens elements includes three cylindrical electroactive lens elements.

15. The electroactive lens according to claim 7, wherein, The stack of cylindrical electroactive lens elements includes four cylindrical electroactive lens elements.

16. The electroactive lens according to claim 7, wherein, The stack of cylindrical electroactive lens elements comprises five cylindrical electroactive lens elements.

17. The electroactive lens according to claim 7, wherein, The stack of cylindrical electroactive lens elements comprises six cylindrical electroactive lens elements.

18. The electroactive lens according to claim 17, wherein, The six cylindrical electroactive lens elements are aligned to provide cylindrical refractive power at the 0, 24, 72, 120, 144 and 168 degree meridians, respectively.

19. The electroactive lens according to claim 7, wherein, Each cylindrical electroactive lens element in the stack of the cylindrical electroactive lens elements is configured to be actuated independently.

20. The electroactive lens according to claim 7, wherein, Each cylindrical electroactive lens element in the stack of the cylindrical electroactive lens elements comprises: Liquid crystal material layer; and An array of linear electrodes electrically connected to the liquid crystal material layer and perpendicular to the optical axis of the electroactive lens, the linear electrodes being configured to apply an electric field to the liquid crystal material layer, thereby enabling the liquid crystal material layer to provide a variable cylindrical optical refractive power orthogonal to the optical axis of the electroactive lens.

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