High definition and extended depth of focus intraocular lens

Abstract

To disclose systems, devices, and methods that overcome limitations of lOLs at least by providing a phakic or aphakic IOL that provides correction of defocus and astigmatism, decreases higher-order monochromatic and chromatic aberrations, and provides an extended depth of focus to improve vision quality.SOLUTION: The IOL includes a virtual aperture integrated into the IOL. The construction and arrangement permit optical rays which intersect the virtual aperture and are widely scattered across the retina, causing the light to be virtually prevented from reaching detectable levels on the retina. The virtual aperture helps remove monochromatic and chromatic aberrations, yielding high-definition retinal images. For a given definition of acceptable vision, the depth of focus is increased over a larger diameter optical zone IOL.SELECTED DRAWING: Figure 16

Description

Technical Field

[0001] (Background Art) This application claims priority to U.S. Patent Application No. 62 / 861,120, entitled "HIGH DEFINITION AND EXTENDED DEPTH OF FIELD INTRAOCULAR LENS", filed on Jun. 13, 2019; U.S. Patent Application No. 62 / 986,115, entitled "HIGH DEFINITION AND EXTENDED DEPTH OF FIELD INTRAOCULAR LENS", filed on Mar. 6, 2020; and U.S. Patent Application No. 62 / 988,802, entitled "MICRO-PRISM REGION FOR EXTENDED DEPTH OF FOCUS INTRAOCULAR LENS", filed on Mar. 12, 2020. The contents of the above-referenced applications are hereby incorporated by reference in their entirety.

Background Art

[0002] The human eye often has aberrations such as defocus and astigmatism, and in order to maintain a high quality of life, these must be corrected to provide acceptable vision. Correction of these defocus and astigmatism aberrations can be achieved using a lens. The lens can be located, for example, on the spectacle surface, the corneal surface (contact lens or corneal transplant), or implanted within the eye as a phakic (intact crystalline lens) or aphakic (crystalline lens removed) intraocular lens (IOL).

[0003] In addition to basic aberrations such as defocus and astigmatism, the eye often has higher-order aberrations such as spherical aberration and other aberrations. Also, the eye has chromatic aberration (which is generally an aberration caused by the change in focus depending on the wavelength of visible light). These higher-order aberrations and chromatic aberration have an adverse effect on the quality of human vision. The adverse effects of higher-order aberrations and chromatic aberration increase as the pupil gets larger. The vision with these aberrations removed is sometimes called high-definition (HD) vision.

[0004] Presbyopia is a state in which the eye loses the ability to focus on objects at different distances. An aphakic eye is presbyopic. A standard monofocal IOL implanted in an aphakic eye restores vision at a single focal distance. To obtain improved vision at various distances, various devices and techniques are used, among which a monofocal IOL is used in combination with bifocal glasses or progressive power glasses. The monovision IOL system is another option for restoring near and far vision - by setting one eye to a different focal distance from the other eye, it provides the combination of both eyes at two focal points and provides a blended visual field. Monovision is currently the most common method for correcting presbyopia, which uses an IOL to correct the dominant eye for distance vision and the non-dominant eye for near vision in order to achieve binocular vision without glasses from far to near.

[0005] In addition, the IOL may be multifocal, for example, bifocal (having two focal regions - typically far and near -) or trifocal (having three focal regions - typically far, intermediate, and near -). Many multifocal IOLs are designed to have one or more focal regions distributed within the addition range. However, using only elements with discrete foci is not the only possible design strategy. The use of elements with extended depth of field (EDOF), i.e., elements that generate continuous focal segments over the required addition (or addition range), can also be considered. These methods are not fully acceptable because stray light from various focal regions can reduce a person's visual acuity. Summary of the Invention

[0006] To improve the quality of vision, a system, device, and method for overcoming the limitations of an intraocular lens (IOL) are disclosed by at least providing a phakic (with a natural lens) or aphakic (without a natural lens) IOL that provides defocus and astigmatism correction, reduces higher-order monochromatic and chromatic aberrations, and provides an extended depth of focus. The IOL includes a virtual aperture incorporated therein. This structure and arrangement allow light rays that intersect the virtual aperture and are widely scattered onto the retina, while effectively preventing the light rays from reaching a detectable level on the retina. The virtual aperture helps to remove monochromatic and chromatic aberrations and enables a high-definition retinal image to be obtained. According to known definitions of acceptable vision, an IOL with a larger diameter optical zone has an increased (deeper) depth of field.

[0007] In one aspect, an intraocular lens for providing extended depth of focus is disclosed, the intraocular lens comprising: an optical zone including at least one anterior optical surface and at least one posterior optical surface; a first peripheral region located peripherally with respect to the optical zone, the first peripheral region including a virtual aperture, the virtual aperture including an anterior virtual aperture surface and a posterior virtual aperture surface; and a second peripheral region located peripherally with respect to the first peripheral region, the second peripheral region being a haptic for positioning the intraocular lens in the eye, the haptic including an outermost region of the intraocular lens. When the intraocular lens is implanted in the eye, a first plurality of light rays incident on the anterior optical surface pass through the optical zone and form an image on the retina. At least: (a) a first surface contour of the anterior surface of the intraocular lens, the first surface contour including at least one annular region; and (b) a second surface contour of the posterior surface of the intraocular lens, the second surface contour including at least one annular region. Any one of . A second plurality of light rays incident on the anterior virtual aperture surface are widely dispersed downstream in the direction of the retina and across the retina from the intraocular lens, whereby the image includes an extended depth of focus. Further, the virtual aperture reduces monochromatic aberration and chromatic aberration of the image.

[0008] In related methods, an IOL, such as an IOL of any of the embodiments described herein, is implanted into or coupled to an eye, such as a human eye. In accordance with the features described herein, the intraocular lens is used to modify or adjust the transmission of light rays onto the retina of the eye.

[0009] Details of one or more variations of the subject matter described herein are set forth in the accompanying drawings and the description below. Other features and advantages of the subject matter described herein will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0010]

Figure 1

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[0011] Before further describing the present subject matter, it is to be understood that the present subject matter described herein is not limited to the specific embodiments described and may, of course, be modified. Also, it is to be understood that the terms used herein are for the purpose of describing particular embodiments only and are not intended to be limiting. All technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this subject matter belongs, unless otherwise defined.

[0012] To overcome limitations of IOLs, there is provided at least a fake or afake IOL that provides defocus (blur) and astigmatism correction, reduces higher-order monochromatic and chromatic aberrations, and provides an extended depth of focus to improve the quality of vision. The disclosed IOLs may be referred to herein as Z+ optics or Z+ IOLs. U.S. Patent No. 10,285,807 and U.S. Patent Application No. 16 / 380,622 describe related systems and methods, both of which are incorporated herein by reference in their entirety.

[0013] Provide an explanation of the basic principles used to reduce monochromatic aberration and chromatic aberration and provide an increased depth of focus. FIG. 1A schematically shows a single converging lens 1 centered on the optical axis 2. Incident light rays 3 from a distant object are parallel to the optical axis and intersect the focal point 4 (which is labeled with a subscript b, c, d, or e based on the corresponding figure) of the lens. The incident light rays 3 are parallel to the optical axis and intersect the focal point 4 of the lens. If the power of the lens is properly selected, the focal point coincides with the observation plane 5; otherwise, there is a mismatch between the power of the lens and the position of the observation plane, and the focal point is in front of or behind the observation plane.

[0014] In FIG. 1A, the focal position is in front of the observation plane. Tracing all incident light rays at the same ray height as the incident light ray 3 results in a blur circle 6 on the observation plane 5. Since the observation plane is in a direction perpendicular to the optical axis, it is shown as a vertical line in the figure. Also, for visualization convenience, the blur circles 6, 8 are shown in the plane of the drawing, but in reality, the blur circles are included in the observation plane. Other incident light rays with a lower ray height than the incident light ray 3 enter inside this blur circle 6. One such ray is the incident light ray 7 closer to the optical axis than the incident light ray 3. The incident light ray 7 also intersects the focal point 4 and further intersects the observation plane 5. Tracing all incident light rays at the same ray height as the incident light ray 7 results in a blur circle 8 smaller than the blur circle 6 being traced.

[0015] Figure 1B shows the same optical system as Figure 1A, but here the incident light rays are for an object close to the optical system, as indicated by the inclination of the incident light rays 3b and 7b. The foci 4 (labeled with subscripts a, b, c, d based on the corresponding figures) for the close object approach the observation plane, and both the blur circles 6b and 8b become smaller than their corresponding parts in Figure 1A. However, the principle is the same that the rays intersecting the lens 1 near the optical axis have a smaller blur on the observation plane. Associating this simple optical structure of Figure 1 with the human eye, the converging lens 1 represents the principal plane of the optical system of the eye, including the cornea and the crystalline lens or intraocular lens. The observation plane 5 represents the retina. As depicted, since the focus 4 is in front of the observation plane (retina), this figure represents myopia or nearsightedness. The size of the blur circles 6, 8 (or 6b, 8b) represents the amount of defocus on the retina, and a smaller diameter of the blur circle provides a sharper field of view compared to a larger one.

[0016] It should be noted that a similar relationship between the height of the incident light ray and the size of the blur circle also holds for presbyopia or farsightedness. This is schematically illustrated in Figures 2A and 2B, which show the light rays corresponding to farsightedness. In Figure 2A for the light rays 3, 7 from a distant object and Figure 2B for the light rays 3b, 7b, the lower the light ray height, the smaller the blur circle on the retina (observation plane).

[0017] Similarly, Figures 3A and 3B (collectively referred to as Figure 3) show that the characteristic relationship between the height of the parallel light rays and the diameter of the blur circle also holds for emmetropia in the same way. For a distant object, the focus 4e is on the retina (since the eye is emmetropic), and the radii of the blur circles 6e and 8e are zero. For a close object, the focus 4f is behind the retina, and the blur circle 8f corresponding to the light ray 7b close to the optical axis has a smaller diameter than the blur circle 6f corresponding to the light ray 3b far from the optical axis.

[0018] Generally, the eye has aberrations, which means that when the position of the incident light ray changes, the focal position within the eye also changes. However, regardless of where the focal position is (in front of the retina, on the retina, or behind the retina), as the height of the incident light ray decreases, the diameter of the blur circle on the retina also decreases. In other words, when there is a certain amount of defocus (dioptric error) in the eye, the visual acuity improves as the height of the incident light ray decreases. This principle is used when trying to see a distant or near object that is out of focus more clearly by narrowing the eyes and blocking the incident light rays away from the optical axis of the eye with the eyelid.

[0019] The ray traces shown in FIGS. 1A to 3B are for incident light of a single wavelength. In the case of polychromatic light, there are multiple wavelengths. As shown in FIGS. 4A and 4B (collectively referred to as FIG. 4), they are generally illustrated by three light rays of different wavelengths. In the components of the eye and typical optical materials, it is well known that the refractive index decreases as the wavelength of light increases.

[0020] In FIG. 4A, the converging lens 21 has an optical axis 22. The colored incident light ray 23 consists of light of three wavelengths: blue (450 nm), green (550 nm), and red (650 nm), which approximately cover the range of visible light. Since the refractive indices of the three wavelengths are different, the blue light ray 24 is refracted more than the green light ray 25, and the green light ray is refracted more than the red light ray 26. If the green light ray is in focus, the green light ray intersects the observation surface 27 on the optical axis. Due to the color spread of these three light rays, a colored blur circle 28 is formed on the observation surface.

[0021] In FIG. 4B, the chromatic incident rays 29 have a lower ray height than the chromatic rays 23 in FIG. 4A. This results in less chromatic blur 33 at the viewing plane. Thus, similar to the monochromatic blur of FIGS. 1A-3B, the lower height of the chromatic rays results in less chromatic blur. The situation in FIG. 4 can be related to the eye by considering the converging lens 21 as the eye's principal plane and the viewing plane 27 as the retina. Since the human eye typically has a large chromatic aberration (approximately 1.0-1.2 diopters over the central visual range), reducing the chromatic aberration can be significant resulting in a noticeable improvement in the quality of the eye's vision, especially as measured by its contrast sensitivity.

[0022] Taken together, Figures 1A-4B show that lowering the beam height reduces both monochromatic and chromatic aberrations at the retina, and therefore improves the quality of vision. This can be achieved by reducing the pupil diameter to block rays that are far from the axis, or by spreading the light from those rays more uniformly and / or more widely across the retina, so that less of the many aberrant rays contribute to the central retinal blur circle. Another feature of this effect is the increased depth of focus as the beam height is lowered, as shown in Figures 1B, 2B, and 3B.

[0023] FIG. 5A shows a converging lens 34 with an optical axis 2 and an aperture 35. A parallel incident ray 36 passes just through the aperture and then through the lens focal point 37, intersecting with the observation plane 38. All parallel rays at the same height as ray 36 trace a small blur circle 39 on the observation plane. A parallel incident ray 40 is blocked by the aperture and cannot proceed to the observation plane and produce a large blur circle 41. Thus, the aperture, which reduces the height of the incident ray, reduces the diameter of the blur at the observation plane.

[0024] FIG. 5B shows a "virtual aperture". That is, it is not an aperture that actually blocks light rays, but the optical effect on the central vision is almost the same. In this figure, the bundle of light rays 40b incident on the virtual aperture propagates through the virtual aperture 42 and is further refracted, diffracted, scattered, and / or reflected, so that the obtained light rays 43 that are widely spread out have little contribution to the blurring light at any one point on the observation surface. This is the main operating mechanism of the disclosed IOL.

[0025] [Exemplary optical layout of an intraocular lens] Figures 6A - 6C show exemplary IOL layouts that employ optical principles to achieve the advantages of reducing monochromatic and chromatic aberrations and increasing depth of focus. FIG. 6A shows a front view of the IOL, which may be a front view. FIG. 6B shows a rear view of the IOL, which may be a posterior view. FIG. 6C shows a side view of the IOL. The IOL includes a central optical zone 46 (having a back surface 46b) that provides defocus, astigmatism, and other corrections required of a lens such as spherical aberration. Generally, an IOL that employs a virtual aperture has a smaller diameter of the central optical zone compared to a conventional IOL. This results in a thinner central thickness, which in turn makes the implantation of the IOL easier and allows for a smaller corneal incision during surgery. The IOL includes a virtual aperture 48 disposed further peripherally outward with respect to the central position of the central optical zone 46. Moving peripherally outward from the virtual aperture 48, at least one IOL haptic 50 (having a back surface 50b) is disposed on the IOL. The haptic 50 can be formed from one or more arms that extend peripherally outward and define the peripheral most edge of the IOL. In one example, the diameter of the optical zone is 1.5 mm. The haptic 50 can define the outermost peripheral region of the IOL. When the IOL is disposed in the eye, a first plurality of light rays incident on the front optical surface of the optical zone can pass through the optical zone and form an image on the retina, while a second plurality of light rays incident on the front surface of the virtual aperture are directed from the IOL in the direction of the retina and widely dispersed downstream across the retina, whereby the image includes an extended depth of focus. Further, the virtual aperture reduces the monochromatic and chromatic aberrations of the image. The optical zone can include at least one of a two - focal optical system, a three - focal optical system, and a multi - focal optical system.

[0026] The virtual aperture is connected to the optical zone 46 by a first transition region 47 located at the periphery of the optical zone 46, and the virtual aperture forms a first peripheral region that surrounds or partially surrounds the optical zone. The haptic can include a second peripheral region for positioning the intraocular lens within the eye. The first transition region is disposed outside the periphery of the optical zone 46. A second transition region 49 connects the haptic 50 to the virtual aperture 48. The first transition region 47 and the second transition region 49 are configured to ensure the zero - order and first - order continuity of the outer surface of the IOL on both sides of each transition region. A common way to achieve this is a polynomial function such as a cubic Bézier function. Such transition methods are known to those skilled in the art. A common way to implement these transition regions is a polynomial function such as a cubic Bézier function. Such transition methods are known to those skilled in the art. On the back side of the IOL, there is a central optical zone 46b, a haptic 50b, and a transition 47b therebetween. FIGS. 6A - 6C are not necessarily to scale, and the shape of the haptic is for illustrative purposes only. Other haptic shapes and sizes known to those skilled in the art would be equally suitable. The first and second transition regions do not necessarily have to be present in the IOL.

[0027] The IOL has a front surface and a rear surface, and each of the components of the IOL including the optical zone 46, the first transition region 47, the second transition region 49, the virtual aperture 48, and the haptic 50 can have respective front and rear surfaces. The optical zone 46 has a front optical surface that can include at least one multifocal zone and / or a toric (circular ring-shaped) region. At least a part or region of the front surface and / or the rear surface, such as the region or other part of the virtual aperture of the IOL, can have a surface contour or shape that can achieve a desired or predetermined effect on the light passing therethrough. In a non-limiting exemplary illustration, the surface contour of the front surface and / or the rear surface includes a region with a ripple-type (corrugated-type) contour such as a wave shape or a undulating shape forming a series of raised and lowered surfaces. FIG. 12 shows an exemplary embodiment of a ripple-like contour, where a series of concentric, annular (or partially annular) ripple-like regions are formed on the surface of the virtual aperture. The ripples can be, for example, annular corrugations or a series of annular corrugations radiating outward from a central position.

[0028] The ripples (or other surface contours) can be arranged in any of various patterns on the rear surface and / or the front surface of the IOL. In certain embodiments, the surface contour is arranged by a series of concentric, annular (or partially annular) shapes, patterns, or regions radiating from a midpoint or other point on the IOL. In another embodiment, the surface contour can be a microprism shape or a series of microcrystalline shapes arranged on the surface. FIG. 13 shows an exemplary embodiment of the microprism shape on the surface of the virtual aperture. The front surface and / or the rear surface can also be smooth surfaces. FIG. 14 shows an exemplary embodiment of the smooth surface of the virtual aperture. Some exemplary embodiments of the microprism structure are described below.

[0029] The virtual aperture and / or microprism region can be present on the front and / or back surface of the IOL. Further, in some applications, it may be beneficial to have one annular portion for the virtual aperture and one annular portion for the microprism region. FIG. 28 shows an example of an embodiment, where a central optical zone 2801 is surrounded by a first annular region 2802, which in turn is surrounded by a second annular region 2803. The first annular region can depict a ripple-like virtual aperture and the second annular region can depict a microprism region, or vice versa. The back surface can have two similar annular structures and those regions can be the same as or inverted from the front surface. Further, the two annular regions may or may not occupy the same extent from the center of the IOL. The IOL can have any number of annular regions with surface profiles on its front or back surface.

[0030] In other applications, it may be beneficial to have more than two such annular regions on the front and / or back surface of the lens.

[0031] It should be understood that a wide variety of combinations of surface profiles or smooth surfaces of the front and back surfaces of the IOL, such as in the region of the virtual aperture for example, are achievable. FIG. 15 is a table showing various combinations of surface profiles of the front and back surfaces.

[0032] The surface profile can achieve various effects with respect to the light passing through the IOL. For example, the surface profile can achieve a wide or wider spread of stray light depending on the type of surface profile used. The surface profile can be used to achieve a spread of stray light that is directed away from the focus of the retina.

[0033] [Examples of details of the optical zone] (Multiple) optical zones are configured to provide improved focused light rays to the eye. In most eyes, good vision is provided by performing improved spectacle correction, i.e., the optical zone corrects (compensates for) the errors of sphere, cylinder, and axis for the eye. The correction of sphere, cylinder, and axis is collectively referred to as astigmatism correction. In addition to astigmatism correction, the spherical aberration of the optical zone is optimally reduced. Correcting spherical aberration means that all or substantially all parallel incident light rays for the optical zone have the same focal position regardless of the height of the light ray. In an aphakic IOL, the shape of the optical zone is selected to have equal conical surfaces. From this previous experience with this design shape and spherical aberration correction, it has been shown that it is less susceptible to the effects of actual positioning errors such as the tilt and decentration of the lens with respect to the optical axis of the eye.

[0034] To determine the astigmatic power of the optical zone for correcting the astigmatism (or astigmatic error) of a particular eye, the clinician uses an IOL power calculation technique or algorithm. The IOL power calculation algorithm is provided as a stand-alone program (such as a software program) or is part of a device that acquires some or all of the eye measurements necessary to perform IOL power calculation. These measurements typically include corneal refractive power (keratometry), anterior chamber depth (measured from the cornea to the iris or lens), and axial length (measured from the cornea to the retina). When these measurements are input into the IOL power calculation algorithm, the theoretical power of the IOL is calculated. Currently, next, an available IOL power close to the theoretical power (usually quantized in 0.5 diopter increments) is selected for implantation in the eye.

[0035] [Calculation of the vertex curvature radius R for each meridian] For the disclosed IOL labeled power (or labeled refractive power) to operate well with the IOL refractive power calculation algorithm, it should preferably be accurate when placed in the eye. Generally, the labeled power includes the refractive error that requires the calculation of two principal refractive powers in two orthogonal principal meridians. The refractive error correction is described as follows. Sphere + Cylinder × Axis Here, the units of the sphere and the cylinder are diopters, and the unit of the axis is degrees (0° to 180°). The two principal refractive powers P1 and P2 are given by Equation (1).

[0036]

Equation

[0037] In this equation, the principal refractive power P1 acts along the meridian defined by the axis, and the principal refractive power P2 acts along the meridian defined by (axis + 90) modulo 180. To calculate the principal optical zone power of the equivalent surface power shape, start with the lens maker's equation given by Equation (2).

[0038]

Equation

[0039] Considering the principal lens power PE (unit: diopter), the central thickness (or center thickness) d of the optical zone (unit: mm), and the refractive index n of the lens material IOL (known to at least three decimal places), the surface principal refractive powers (unit: diopter) of the IOL optical zone are given by Equation (3).

[0040]

Equation

[0041] The main parameters involved in the calculation of the surface refractive powers P1 and P2 (unit: diopter) are schematically shown in FIG. 7. FIG. 7 schematically shows the optical axis 51 passing through the center of the front surface (or anterior surface) 52 and the back surface (or posterior surface) 53 of the IOL optical zone. The front surface 52 and the back surface 53 are equivalent, that is, they are both conic curves with the same vertex curvature radius Ra (mm) and conic constant K. The front and back surfaces are separated at the central portion of the central thickness d (mm) 54. The refractive index n of the lens material in situ is known IOL has 55, and the medium surrounding the lens in the eye has the refractive index n EYE 56.

[0042] Once the principal meridian refractive powers P1 and P2 of the optical zone surface are obtained using equations (1) to (3), the power of each meridian θ is calculated using equation (4).

[0043]

Equation

[0044] Next, when the power (diopter) at the meridian θ is given, the surface curvature radius R(θ) (mm) at that meridian is calculated using equation (5).

[0045]

Equation

[0046] In this equation, n IOL = refractive index of the IOL material n EYE = refractive index of the medium inside the eye (1.336) P(θ) = power at the meridian θ R(θ) = radius at the meridian θ is.

[0047] Using equations (1) to (5), an equal toric optic zone surface can be calculated, where each meridian θ has a radius of curvature R(θ). If cylinder = 0 in equation (1), the radius is constant for each meridian, and R(θ) = R.

[0048] [Calculation of the optimized conic coefficient K for each meridian] To provide correction of spherical aberration, each meridian profile is represented by a conic curve, and the conic constant K is optimized to optimally reduce spherical aberration. The conic curve [3] is given by equation (6).

[0049] [Equation]

[0050] In this equation, x = distance along the optical axis (mm), positive to the right y = distance perpendicular to the optical axis (mm), positive upward r = vertex curvature radius (mm) K = conic constant (dimensionless), K = 0 for a circle is the case.

[0051] Solving equation (6) for x gives the equation for the sag of the curve as shown in equation (7).

[0052] [Equation]

[0053] The derivative of the conic sag is given by equation (8).

[0054] [Equation]

[0055] The analytical derivative of Equation (8) can also be numerically approximated by those skilled in the art using a difference operator such as, for example, a forward, backward, or central difference equation, and can be a first-order or higher-order difference equation. This derivative is used when computationally calculating the normalized tangent vector T(y) shown in Equation (9).

[0056]

Number

[0057] As will be described below, this tangent vector is used to match the transition zone tangent vectors to provide first-order continuity between the transition zones and the curve profiles to which they are connected.

[0058] Once the vertex curvature radius at a given meridian R(θ) is obtained, an optimal conic constant K(θ) is calculated to minimize spherical aberration. In a conventional method of optimizing the conic constant of an equiangular conical IOL optical system (described in U.S. Patent No. 7,350,918), only a single meridian and a single ray height were considered to obtain a single conic constant for the entire surface. With this single meridian / single ray height, optimization was performed using the Newton-Raphson iterative method to make the longitudinal aberration (or longitudinal ray aberration) zero. In this case, the conic constant is optimized for each meridian. This optimization is performed using a dense set of incident ray heights along the meridian to determine the resulting ray height at an observation plane located at the back focal point of the optical zone. The position of the back focal point is given by Equation (10).

[0059]

Number

[0060] In this equation, n IOL = refractive index of the IOL material n EYE= Refractive index of the medium inside the eye (1.336) P = Diopter at meridian θ (unit: diopter) BFL = Back focal length (unit: mm) is as follows.

[0061] During optimization, a comprehensive search is performed for the conic constant K value to find the value that minimizes the cost function E. This cost function E is given by Equation (11).

[0062] [Number]

[0063] In this equation n = Indexer for the traced ray, (0 to N - 1). N = Number of traced rays y0(n) = Height of the incident ray n on the front surface of the optical zone y1(n) = Height of the ray n on the observation surface located at the back focal point p = Error power of the horizontal ray, a scalar that controls the behavior of the cost function (scalar value) is as follows.

[0064] In the cost function equation, the lateral ray error y1(n) is weighted by the height y0(n) of the corresponding incident ray in order to account for the optical sector area it represents. For certain applications, an appropriate value for the lateral ray error refractive power p is 3. This value is chosen as a compromise between p = 2 (which specifies the typical Euclidean norm and is related to the RMS error) and p = ∞ (which is the maximum error or the infinity norm). Selecting this value for p provides an excellent error norm for the application, as the maximum value of the lateral ray error is smaller than that resulting from typical RMS optimization, and yet most of the values of the lateral ray error remain smaller than the maximum error that would exist in the case of the infinity norm. This exhaustive search-based optimization of K is performed at equally spaced incident ray heights of N = 10,000 over the range K = (-1 to 0) to determine the optimal K to four decimal places.

[0065] Figure 8 schematically shows a single ray 57 in this optimization calculation of the IOL. The incident ray 58 with ray height y0 propagates from left to right to the front surface 59 of the optical zone. The emergent ray 60 exits the back surface 61 of the optical zone, intersects the observation surface 62, and then intersects the optical axis 63. The longitudinal ray error 64 is the distance from the focal point 65 to the intersection with the emergent ray on the optical axis. The lateral ray error 66 is the distance from the focal position 65 to the intersection of the emergent ray with the observation surface 62. The values used in the cost function equation are the height y0 of the incident ray 58 and the height y166 when the emergent ray 60 intersects the observation surface 62.

[0066] An example of the range of values for this optical zone is as follows.

[0067]

Table 1

[0068] [Method for calculating the diameter of the optical zone] A simple formula for estimating visual acuity by giving the pupil diameter and spherical refractive error is shown below. They are given by Equation (12) and Equation (13).

[0069]

Number

[0070]

Number

[0071] Here, A = visual acuity (unit: minute of arc) (A = Sd / 20), that is, the minimum angle of resolution. k = a constant determined from clinical studies, and the average value is 0.65. D = pupil diameter (unit: mm) E = spherical refractive error (unit: diopter) Sd = Snellen denominator That is.

[0072] The second formula is assumed to be more accurate for low levels of refractive error, gives a valid result when E = 0, and gives A = 1 minute of arc or 20 / 20.

[0073] Solving Equation (13) for E gives Equation (14).

[0074]

Number

[0075] Equation (13) gives the visual acuity A when given the range of depth of focus (E×2) (unit: diopter) and the pupil diameter D, and Equation (14) gives the range of depth of focus in diopters when given the visual acuity A and the pupil diameter D. For example, in the following cases. Visual acuity 20 / 40, A = 40 / 20 = 2 minutes of arc D = 3.0 mm k = 0.65

[0076] [Mathematics]

[0077] The depth of focus = 2E = 1.8D. Using Equation (13),

[0078] [Mathematics]

[0079] Note that these equations regarding visual acuity and depth of focus are only approximate equations and do not include the influence of diffraction. Using A = 2(20 / 40 visual acuity), the approximate values of the depth of focus at the following three main diameters are calculated as follows.

[0080] [Table 2]

[0081] [Details of Virtual Aperture] The following variables are defined for the virtual aperture IOL.

[0082] [Table 3]

[0083] The virtual aperture plays a role, either wholly or in part, in spreading the incident light rays intersecting the front surface of the virtual aperture over the entire retina. In an exemplary embodiment, the virtual aperture includes, on the front surface, alternating high-power positive and negative profiles, and a smooth curve connecting the back surface of the optical zone to the haptic on the back surface. This is shown in FIG. 9. This figure shows the optical axis 67, the central thickness 68, the edge thickness 69 and the surface landmark point y~P9 of the IOL. The profile of FIG. 9 represents the upper half of the IOL and is not necessarily drawn to scale. The front surface 76 shows the front optical zone between point P0 and point P1 and has a radius (OZD / 2) 71 of the optical zone. The first transition region of the front surface has a width 72 and is located between point P1 and point P2. The virtual aperture has a width 73 and is located between point P2 and point P3. The second transition region of the front surface has a width 74 and is located between point P3 and point P4. The front haptic surface has a width 75 and is located between point P4 and point P5. The back surface 77 has a back haptic surface with a width 78 and is located between point P6 and point P7. The back surface transition region has a width 70 and is located between point P7 and point P8. The radius of the whole lens is reference numeral 79. The position of the nominal virtual aperture reference line is 80.

[0084] The surface landmark points are located at positions starting from P0=(0,0). In FIG. 9, the X-axis increases in the right direction and the Y-axis increases in the upward direction. The coordinates of these points are as follows.

[0085] [Surface landmark points]

[0086]

Table 4

[0087] Figure 10 shows the details of the virtual aperture profile for the IOL, which is not necessarily drawn to scale. The virtual aperture 43 is shown as a continuous thick line with a varying radius of curvature on the left side of this figure, starting from the bottom and having an alternating concave / convex / concave... shape. The lowest point P2 in this figure corresponds to point P2 in Figure 9. Similarly, the highest point P3 in this figure corresponds to point P3 in Figure 9. The circular area at the bottom left is enclosed by a dashed circle and is enlarged on the right side of this figure. The enlarged part of the figure shows a circular concave portion having a surface profile VS0, a center VC0 of the circle, a vertex VA0 of the circle, a starting point VP0 of the circle, and an ending point VP1 of the circle. These three points VP1:VC0:VP0 form a right angle as shown by the small square at VC0. The virtual aperture nominal reference line 81 is a vertical line and includes the boundary points between the alternating circular surface profiles VS0, VS1, etc. Knowing that this is the cross-section of a circle with a radius of curvature r0, the following vector relationships can be obtained.

[0088]

Number

[0089]

Number

[0090]

Number

[0091] In an exemplary embodiment, in the virtual aperture profile, when J is an even number, for example, there are 14 circular surface profiles arranged alternately. Each of these circular surface profiles VSj has a corresponding center VCj, a starting surface point VPj, a surface vertex VAj, an ending surface point VP(j + 1), and a radius rj. Given a series of radii rj of length J and the width of the virtual aperture region VAFW, a scale factor S is calculated such that when all the radii are multiplied by S, the virtual aperture exactly matches its desired width. This scale factor is calculated using Equation (18).

[0092]

Number

[0093] After calculating the scale factor, multiply the series of rj values by S to obtain the set of radii used to determine the final virtual aperture profile. A preferred set of radii for the virtual aperture is randomly selected in the range of 0.05 - 0.10 mm. When the width of the virtual aperture is 2.05 mm and the average radius of one circle is 0.075 mm, there are approximately J circles obtained by the following formula.

[0094]

Number

[0095] Examples of the radii of 18 circles providing a virtual aperture with a width of 2.05 mm are shown below.

[0096]

Table 5

[0097] And when the starting point P2 and the continuous circular profile are given, a circular shape of the virtual aperture profile that exactly matches the desired virtual aperture width is constructed.

[0098] In an alternative embodiment, the radii r of the successive circular profiles are made equal and, given the number J of circular surface profiles arranged alternately and the width of the virtual aperture region VAFW, the equal radii are given by Equation (19).

[0099] [Number]

[0100] [Details of the transition region] In an exemplary embodiment, the front transition region of the IOL provides (1) a smooth blend between the outer edge of the front central optical zone and the inner edge of the front virtual aperture, and (2) a smooth blend between the outer edge of the front virtual aperture and the inner edge of the haptic front. The back transition region provides a smooth blend between the outer edge of the back central optical zone and the inner edge of the haptic back. These transition regions can generate a set of surface points for a lathe file, or other manufacturing apparatus such as a laser.

[0101] To smoothly blend or connect the various regions of the lens, i.e., to provide at least zero and first order continuity between these regions, a cubic Bézier curve is employed. The smoothness of the transition regions can prevent visual artifacts. The two-dimensional (and three-dimensional) parametric Bézier curve F(t) is given by Equation (20).

[0102] [Number]

[0103] where n = the degree of the Bézier curve, n = 3 for cubic t = the parametric variable which goes from 0 to 1 as the curve goes from the first control point to the last control point. p i = control point is.

[0104] Since the blending function adopted here is a cubic Bézier curve, there are four points from p0 to p3. The width of the transition region (unit: degree) is given by the variable WT. The cubic Bézier curve passes through point p0 at t = 0 and point p3 at t = 1. If the end points p0 to p3 are set equal to the last points of the surface connected in the transition region (for example, points P1 and P2 in Fig. 9), the zero - order continuity is guaranteed. The derivative of the curve at point p0 is equal to the slope of the straight line from p0 to p1. The derivative of the curve at point p3 is equal to the slope of the straight line from p2 to p3. Therefore, it can be important to place the control point p1 along a straight line passing through point p0 (the end of the curve in the previous region) and having the same slope as the slope at p0 that forms the previous curve. The same applies to the placement of point p2. These constraints on the control points p1 and p2 ensure the first - order continuity at the ends of the regions connected by the transition curve.

[0105] The four Bézier control points form the convex hull of the Bézier curve. The influence of the intermediate control points p1 and p2 on the shape of the curve increases and decreases as the distances from the boundary points p0 and p3 are changed. To control the placement of these intermediate control points within the blending region, a parameter called FT (transition fraction) is used.

[0106] When the FT value is made small (e.g., 0.1), the intermediate control points p1 and p2 are kept near their respective end control points p0 and p3. When the FT value is small, the blend curve derivative is not maintained at the very far ends of the blending region. When the FT value is made large (e.g., 0.5), the intermediate control points are pushed towards the center of the blending region. When the FT value is large, the blend curve derivative endpoints are maintained deeper within the blending region. In this way, FT can control the characteristics of the transition curve within the blending region.

[0107] To optimize the transition curve or otherwise improve smoothness to thereby prevent visual artifacts, in addition to maintaining 0th and 1st order continuity at the endpoints as described above, the cubic Bézier in the transition region may have minimum curvature at all points along the curve. The curvature of the cubic Bézier curve is calculated using Equation (21).

[0108]

Number

[0109] Equation (21) states that the curvature C(t) at a point given by the parametric variable t is the norm of the cross-product of the first and second derivatives divided by the cube of the norm of the first derivative. The cubic Bézier vector function and its first and second derivatives are given by Equations (22), (23), and (24).

[0110]

Number

[0111]

Number

[0112]

Number

[0113] In these equations, p0 to p3 are the four control points of the cubic Bézier. As described above, the points p1 and p2 are selected such that the first derivatives at the endpoints p0 and p3 match the connecting regions. Here, the normalized tangent vectors at p0 and p3 are defined using Equations (25) and (26).

[0114]

Number

[0115]

Number

[0116] These normalized tangent vectors can also be reached by directly evaluating the vicinity of the region mixed at points p0 and p3. Then, in the search for the cubic Bézier curve with the minimum curvature, the internal control points p1 and p2 are set according to equations (27) and (28).

[0117]

Number

[0118]

Number

[0119] In these equations, s is the distance between the end points p0 and p3, and frac is the scalar value between (0, 1) to be determined that minimizes the curvature of equation (20) at all points along the Bézier curve. For further illustration, two Bézier curves with end point positions p0, p3 and tangent vectors T0, T3 are shown in Fig. 11A. One has a significantly larger curvature than the other, and the other is optimized to minimize the maximum curvature. The corresponding curvature graphs are shown in Fig. 11B. Fig. 11B shows that the maximum curvature of the non-optimized Bézier is about 2.6, while that of the optimized Bézier curve is about 0.5. This corresponds to a curvature radius of 0.4 for this high-curvature Bézier and 2.0 for the optimized Bézier curve. This not only results in a smooth transition curve with minimal visual artifacts, but also enables the lathe cutting tool to have a radius five times larger for curves with large curvatures.

[0120] To summarize the calculation of the Bézier curve transition zone, the following steps are executed.

[0121] Set the end points p0 and p3 to the corresponding end points of the equation of the connected surface profile.

[0122] Using the equation of the connected surface profile, calculate the tangent vectors T0 and T3 at the end points.

[0123] To minimize the curvature C(t) over the range [0, 1], perform an exhaustive search over the range [0, 1] for frac.

[0124] Using the optimized frac value, computationally calculate the interior points p1 and p2.

[0125] Using the four Bézier points p0 to p3, computationally calculate the transition curve profile using Equation (22).

[0126] The virtual aperture may be located on the back side of the IOL instead of the front side, or the virtual aperture may be located on both the front and back sides of the IOL. The same applies to the microprism region. The optical zone shown in FIG. 1 is biconvex, but the optics may be meniscus-shaped or biconcave depending on the desired optical power of the lens and its use as either a fake or afake IOL.

[0127] [Example of Microprism Virtual Aperture Structure] An example of the profile of an extended depth of focus IOL is shown in FIG. 16, which shows a side view of the IOL lens and is symmetric with respect to the horizontal middle axis. The IOL has a front surface and a back surface. Due to its symmetry, only the upper half of the lens is described. The lens profile has an optical axis 161 passing through the center of the lens. The front surface has a front optical zone 162, a rippled virtual aperture zone 163, and a haptic 164. The back surface has a transition zone 165 connecting the microprism region 166 to the haptic 164, a microprism region 166, a transition zone 167 connecting the microprism region 166 to the optical zone 168, and a back optical zone 168.

[0128] FIG. 17 shows an exemplary contour of a transition zone connecting the microprism region 166 to the haptic 164. The edge of the haptic 164 is connected to the peripheral - most section of the microprism region 166 by a fillet 1710 having at least one of a curved, rounded, or circular contour.

[0129] FIG. 18 shows details of the geometric shape of an exemplary circular fillet 1710. The circular fillet 1710 is specified by its center 1712, radius 1713, start point 1714, and end point 1715. To calculate the fillet specifications, the fillet radius, the intersection point 1716 of the line segments 1717, 1718 connected by the fillet, and the unit - length direction vectors 1719, 1720 parallel to the line segments 1717, 1718 respectively are provided. These given data are represented as follows.

[0130] r = fillet radius, scalar P = intersection point with the line segment, vector of length 2 D0, D1 = unit - length direction vectors parallel to the line segments, vectors of length 2

[0131] The light rays 1721, 1722 parallel to the line segments 1717, 1718 respectively are configured as follows.

[0132]

Equation

[0133] Here, each light ray is defined by a start point and a unit - length direction vector. The start points P0 and P1 of the light rays are identified as items 1723, 1724 in FIG. 18. The intersection point of these two light rays is the center 1712 of the fillet circle. This intersection point 1712 is obtained by solving for the parameter t0 or t1 from Equation (30) and substituting its value into Equation (29) of the above - mentioned light rays.

[0134]

Number

[0135] In equation (30), the columns of the 2×2 matrix on the right side contain the vectors D0, -D1. Let the center of the circle be C. For the specifications of the remaining fillets, the points P a , P b are calculated using equation (31).

[0136]

Number

[0137] The fillet circles connecting the micro prism region to the haptic region are configured to provide a smooth transition in some abrupt designs to prevent visual artifacts that may exist at this position. Other methods such as Bézier curves known to those skilled in the art can also be used for this smooth transition.

[0138] Figure 19 shows an exemplary geometric shape of a transition zone connecting the micro prism region to the optical zone. The edge of the optical zone 1825 is connected to the first section of the micro prism region 1826 by a circular fillet 1827.

[0139] Figure 20 shows the details of a circular fillet connecting the optical zone to a micro - prism segment. The circular fillet is specified by its center 1928, radius 1929, start point 1930, and end point 1931. To calculate the fillet specifications, the fillet radius, the start point 1930 of the edge of the optical zone connected by the fillet, the tangent vector per unit length 1932, and the slope of the micro - prism segment 1926 are provided. The given data is expressed as follows.

[0140] r = Fillet radius, scalar P a = Starting point, vector of length 2 T = Tangent vector of unit length that continues with the same slope as the end point of the optical zone, vector of length 2 s = Slope of the microprism segment, scalar

[0141] The tangent vector T can be calculated analytically from an equation representing the optical zone profile such as a conic equation, or numerically using a difference equation. The difference equation may be a forward, backward, or central difference equation, and may be a first-order or higher-order difference equation. For example, if the optical zone has a circular profile and it can represent either a stigmatic or astigmatic optical zone centered on the optical axis at point C o , the tangent vector T of unit length is given by Equation (31b).

[0142]

Equation

[0143] Also, in FIG. 20, dashed line 1933 and dashed line 1934 are illustrated. The region below line 1934 is the optical zone, the region above line 1933 is the microprism zone, and the region between line 1933 and line 1934 is a transition zone realized as a fillet circle. The center C 1928 of the fillet circle is obtained using Equation (32).

[0144]

Equation

[0145] To find the end point 1931 of the fillet specification, locate the point on the circle where the slope of the microprism segment 1926 matches the slope of the fillet circle. The coordinates of this end point 1931 are given by Equations (33a) and (33b).

[0146]

Number

[0147] The fillet circle connecting the micro - prism area to the optical zone is intended to provide a smooth transition in some abrupt designs to prevent visual artifacts that may exist at this location. For this smooth transition, other methods such as Bézier curves known to those skilled in the art can also be utilized.

[0148] In an exemplary embodiment, the micro - prism array profile is disposed on the back surface of the IOL. The micro - prism profile functions using a combination where some rays are refracted and others are totally reflected, and some rays will be both refracted and totally internally reflected. In the following discussion, the micro - prism array profile is located on the back surface of the IOL and light travels from left to right, i.e., into the eye.

[0149] Figure 21 shows an example of a basic micro - prism array profile. The hatched portion of the array represents the interior of the IOL and the front surface of the IOL is not shown. The refractive index N1 inside the IOL is greater than the refractive index N2 outside the IOL. Typical values of N1 and N2 are 1.459 and 1.336, respectively. Ray 2035 intersects the surface of the micro - prism having surface normal 2037 at intersection 2036. This incident ray 2035 forms an incident angle 2038 with respect to the surface normal 2037. Snell's law describes how ray 2035 refracts at intersection 2036 and is given by Equation (34).

[0150]

Number

[0151] In this equation, the angle of incidence is designated as A1 and the angle of refraction as A2. In the figure, A1 corresponds to item 2038 and A2 corresponds to item 2039. For example, using typical values of N1 and N2, if the angle of incidence 2038 is 45 degrees, the angle of refraction 3209 is 50.6 degrees. A small amount of light reflected around point 2036 is typically negligible and thus not shown in FIG. 21. Refraction acts in this way until the angle of incidence 2038 becomes greater than the so-called critical angle A c greater than this. At angles of incidence greater than the critical angle, the light ray is reflected at intersection point 2. The critical angle is calculated from equation (35).

[0152] [Number]

[0153] Using the above typical refractive index values N1 and N2, the critical angle is 66.3 degrees. In FIG. 21, the incident light ray 2041 intersects the microprism surface at intersection point 2042 having a surface normal 2043. This incident light ray 2041 forms an angle of incidence 2044 with respect to the surface normal 2043. If the angle of incidence is 70 degrees, then according to equation (35), the light ray is totally reflected at surface point 2042 and has a reflection angle 2045 equal to the angle of incidence 2044, resulting in a reflected light ray 2046. The subsequent path when the reflected light ray 2046 is refracted at the microprism surface is not shown in FIG. 21.

[0154] In an exemplary embodiment, the array of microprisms across the microprism region is not uniform. This non-uniformity is illustrated in FIG. 22. In FIG. 22, the total height 2147 is the distance from the end of the optical zone at the bottom of the figure to the start of the haptic at the top of the figure. FIG. 22 shows 4.5 microprisms. The microprisms decrease in size from the bottom to the top of the figure, but the position of the base of each microprism remains along a single X value shown as a dashed vertical line in the figure. Although the size of the microprisms decreases, the slope of each of the lower and upper segments of the microprisms is constant.

[0155] The slope 2148 of all segments is a constant value of 0.5, and the slope 2049 of all segments is a constant value of -0.5. By reducing the size from the center (lower part of the figure) to the peripheral part (upper part of the figure) of the lens, the thickness of the lens from the center to the haptic can be decreased, which is typical in an IOL. The height of each microprism decreases in size from the lower part to the upper part according to a geometric series. For example, the height 2150 of a microprism is equal to the height 2151 of the previous microprism multiplied by a multiple a, where the multiple is less than 1. In the literature, this multiple a is also called the common ratio and is given the symbol r. However, since the symbol r has already been used to denote the fillet radius, an alternative symbol a was chosen. The starting point P of the edge of the optical zone A 2154, the end point P where the haptic starts B 2155, given the slope s of the microprism and the common ratio a, the geometric shape of the geometrically scaled (geometrically enlarged / reduced) microprism can be calculated using the following method.

[0156] The starting point P 2156 of the first complete microprism illustrated in FIG. 22 is given by Equation (36).

[0157]

Equation

[0158] The height h0 2151 of the base of this first microprism is given by Equation (37).

[0159]

Equation

[0160] The height of the base of a series of microprisms is given by Equation (38).

[0161] [Number]

[0162] The sum of the heights of the individual bases gives the total height H and is calculated using Equation (39).

[0163] [Number]

[0164] The approximate number N of the individual microprisms is calculated from Equation (40).

[0165] [Number]

[0166] When the integer value of the number N of the individual microprisms calculated by Equation (12) is given, finally, the initial base width h0 is narrowed down (or refined) so as to exactly become point P B 2155. This fine adjustment for the initial base width is performed using Equation (41).

[0167] [Number]

[0168] For successive microprisms, the peak Peak and valley Valley points of each microprism n = 0,... N - 1 are calculated using Equation (42). n and valley Valley n points are calculated using Equation (42).

[0169] [Number]

[0170] After the peaks of these ridges and valleys are positioned, as shown in FIG. 23, fillets of the ridges and valleys are applied. These fillets are calculated using the method described with FIGS. 18 and equations (29) to (31). Respecting the appropriate sign convention for these fillets, the valley fillet (concave) shall have a positive radius and the ridge fillet (convex) shall have a negative radius.

[0171] For example, the first valley fillet is shown as item 2460 in FIG. 24. The vertical dashed line 2462 in FIG. 24 coincides with the peak of each valley fillet and has the same x - coordinate value X V . Also, the center CV 2465 of each valley fillet has the same x - coordinate as the x - coordinate given by equation (43).

[0172]

Equation

[0173] In this equation, r V is the radius of the valley fillet. The center CV of each valley fillet has the corresponding y - coordinate given from the Valley n point given by equation (42). In FIG. 24, let the bounding points of the fillet circle be P0 2463 and P1 2464. The coordinates of point P0 and point P1 are given by equation (44).

[0174]

Equation

[0175] In these equations, the subscript n represents the number of the valley. As shown in FIG. 24, a positive value is given to the radius r V of the valley fillet circle.

[0176] For the ridge fillet illustrated as item 2461 in FIG. 24, first, the ridge is obtained by equation (42), and then the center CP of the ridge fillet circle is obtained by equation (45).

[0177] [Number]

[0178] In this formula, r P is the radius of the crest fillet circle. Similar to the start and end points of the trough, the start point P0 and the end point P1 of the crest fillet circle are calculated using Equation (46), respectively.

[0179] [Number]

[0180] FIG. 24 illustrates the center, start point, and end point of the crest fillet circle as items 2468, 2466, and 2467, respectively.

[0181] FIG. 25 illustrates how light rays are distributed through a Z+IOL having a front ripple zone and a smooth rear zone. FIG. 26 illustrates that when the rear surface is replaced with one incorporating a microprism region, the spread of light rays across the retina is improved.

[0182] As an alternative to the circular fillets described above, one of ordinary skill in the art may use other transition methods such as Bézier curves.

[0183] In some applications, it may be advantageous to use random fillet radii and / or values for the tilt of the microprisms.

[0184] [Values and Value Ranges of Exemplary Embodiments] In an exemplary embodiment, specific values are selected for the microprism features described above. Additionally, these values may be selected from a reasonable range around the preferred values. These values and ranges are listed in the following table.

[0185] [Table 6]

[0186] [Barrier for PCO (Posterior capsule opacification)] As a complication that can occur after cataract surgery, there is PCO (Posterior capsule opacification). In order to reduce the migration of cells into the virtual aperture or the microprism region, the haptic may have sharp square (or rectangular) edges. Further, the last peak of the microprism region does not necessarily have to have a fillet on the peak. Such a sharp last peak is illustrated as peak 2559 in FIG. 27.

[0187] To use the concepts described above for the surface of the Z + IOL, the following is performed. First, the central optical zone of the IOL is specified. The diameter of the optical zone is, in a non-limiting example, between about 1.5 mm and (1.4 - 1.6 mm). The optical powers of this optical zone vary from -10D to 40D in 0.25D or 0.5D increments. The cylinder powers (or astigmatic powers) for toric IOLs vary from 0.5D to 6.0D in 0.25 - 0.5D increments.

[0188] Next, the virtual aperture is generated using the concepts described in the previous disclosure. The width of the virtual aperture region is about 2.0 mm.

[0189] The widths of the front transition regions are each set to about 0.15 mm. The dimensions of the back microprism region are described in the above table.

[0190] After defining the front and back surfaces, individual profile samples are taken from the center to the periphery of the IOL, and the points for lathe cutting files are specified.

[0191] This specification includes many specifications, but these should not be construed as limiting the scope of the invention described or that can be described in the claims. Rather, they should be construed as descriptions of features that embody particular embodiments. In the context of separate embodiments, the particular features described herein can also be implemented in combination in a single embodiment. Conversely, the various features described in the context of a single embodiment can also be implemented separately or in any suitable sub-combination in multiple embodiments. Furthermore, even if a feature is described as acting in a particular combination and was initially claimed as such in the application, one or more features of the combination described in the claims can, in some cases, be deleted from the combination, and the combination described in the claims can also be directed to a particular sub-combination or a variation of a sub-combination. Similarly, although operations are depicted in the drawings in a particular order, this should not be understood to mean that such operations are required to be performed in the particular order or sequence shown, or that all of the operations shown are required to be performed, in order to achieve a desired result. Only some examples and implementations are disclosed. Variations, modifications, and extensions to the disclosed examples and implementations, as well as other implementations, can be made based on the disclosed content.

Claims

1. An intraocular lens for providing an extended depth of focus, the intraocular lens comprising: An optical zone including at least one front optical surface and at least one rear optical surface; A first peripheral region located peripherally with respect to the optical zone, the first peripheral region including a virtual aperture, the virtual aperture including a front virtual aperture surface and a rear virtual aperture surface; and A second peripheral region located peripherally with respect to the first peripheral region, the second peripheral region being a haptic for positioning the intraocular lens within the eye, the haptic including the outermost region of the intraocular lens; When the intraocular lens is implanted in the eye, a first plurality of light rays incident on the front optical surface pass through the optical zone and form an image on the retina, At least, (a) A first surface profile of the front surface of the intraocular lens, the first surface profile including at least one annular region; and (b) A second surface profile of the rear surface of the intraocular lens, the second surface profile including at least one annular region, Any one of which, A second plurality of light rays incident on the front virtual aperture surface are widely dispersed downstream from the intraocular lens in the direction of the retina and across the retina, whereby the image includes an extended depth of focus, and further, the virtual aperture reduces monochromatic aberration and chromatic aberration of the image. An intraocular lens.

2. The intraocular lens according to claim 1, wherein the intraocular lens includes both the first surface profile and the second surface profile.

3. The intraocular lens according to claim 1, wherein the first surface profile includes at least one of a ripple and a microprism.

4. The intraocular lens according to claim 1, wherein the second surface profile includes at least one of a ripple and a microprism.

5. The intraocular lens according to claim 1, wherein the first surface profile includes a first annular region formed from at least one ripple and a second annular region formed from at least one microprism.

6. The intraocular lens according to claim 1, wherein the second surface profile includes a first annular region formed from at least one ripple and a second annular region formed from at least one microprism.

7. The intraocular lens according to claim 1, wherein the first surface profile is located at the virtual aperture.

8. The intraocular lens according to claim 1, wherein the second surface profile is located at the virtual aperture. **Claim 9** The intraocular lens according to claim 1, wherein the first surface profile includes at least one ripple. **Claim 10** The intraocular lens according to claim 1, wherein the optical zone is separated from the virtual aperture by a first transition region. **Claim 11** The intraocular lens according to claim 1, wherein the virtual aperture is separated from the haptic by a second transition region. **Claim 12** The first surface profile includes ripples at the virtual aperture. The intraocular lens according to claim 1, wherein the second surface profile includes microprisms at the virtual aperture. **Claim 13** The intraocular lens according to claim 12, wherein the virtual aperture is separated from the haptic by a second transition region including a fillet. **Claim 14** The intraocular lens according to claim 13, wherein the fillet has a curved profile. **Claim 15** The intraocular lens according to claim 1, wherein the second surface profile includes peaks of microprisms. **Claim 16** The intraocular lens according to claim 15, wherein the peaks of the microprisms provide a PCO barrier. **Claim 17** A method for treating an eye, comprising: implanting an intraocular implant into the eye, the intraocular implant comprising: an optical zone including at least one anterior optical surface and at least one posterior optical surface; a first peripheral region located peripherally with respect to the optical zone, the first peripheral region including a virtual aperture, the virtual aperture including an anterior virtual aperture surface and a posterior virtual aperture surface; and a second peripheral region located peripherally with respect to the first peripheral region, the second peripheral region being a haptic for positioning the intraocular lens in the eye, the haptic including the outermost region of the intraocular lens; when the intraocular lens is implanted in the eye, a first plurality of light rays incident on the anterior optical surface pass through the optical zone and form an image on the retina, at least (a) a first surface profile of the anterior surface of the intraocular lens, the first surface profile including at least one annular region; and (b) a second surface profile of the posterior surface of the intraocular lens, the second surface profile including at least one annular region, wherein it is any one of A method of treating an eye, wherein a second plurality of light rays incident on the front virtual aperture surface are widely dispersed downstream from the intraocular lens in the direction of the retina and across the retina, whereby the image includes an extended depth of focus, and further, the virtual aperture reduces monochromatic aberration and chromatic aberration of the image.

Images