Patent ID: 12213876

DETAILED DESCRIPTION OF THE INVENTION

Embodiments herein disclosed relate to lenses having refractive power-progressive profiles, e.g., lenses having a refractive aspheric profile that provides a continuous power progression to extend depth of focus (EDF). Some embodiments herein disclosed relate to lenses having refractive power-progressive profiles in conjunction with diffractive profiles, which provide improved depth of focus to a patient. According to some embodiments, a diffractive lens can partially correct for ocular chromatic aberration.

Embodiments of lenses herein disclosed can be configured for placement in the eye of a patient and aligned with the cornea to augment and/or partially replace the function of the crystalline lens. In some embodiments, corrective optics may be provided by phakic IOLs, which can be used to treat patients while leaving the natural lens in place. Phakic IOLs may be angle supported, iris supported, or sulcus supported. IOLs can be further secured with support members that attach the IOL to the eye, e.g., with physical extensions from the IOL into adjacent corneal or iris tissue. Phakic IOLs can also be placed over the natural crystalline lens or piggy-backed over another IOL. Exemplary ophthalmic lenses include contact lenses, phakic lenses, pseudophakic lenses, corneal inlays, and the like. It is also envisioned that the lens shapes disclosed herein may be applied to inlays, onlays, accommodating IOLs, spectacles, and even laser vision correction.

In various embodiments, an intraocular lens can include a first region having a nonzero relative power respect to the base power of the lens and a second region defining a base power that extends to the periphery of the lens. The first region can be radially symmetric about an optical axis of the lens and extend part of a distance from the axis to the periphery. The second region can be an aspheric surface which extends from the outer diameter of the first region to the lens periphery. The second region can have a relative power of approximately zero throughout substantially all of the zone while exhibiting aspheric profile configured to match the elevations of the first region at the first region outer diameter, such that the first and second regions merge smoothly at the boundary between the zones. In embodiments, the first and second regions can be described by a unique surface function, such that there are no discontinuities or abrupt breaks in an add profile across the lens. Regions can be defined as portions of the lens described by the radius of the zones that are fitted to the aspheric equation. Therefore, region boundaries need not equate to physical boundaries because the lens has a continuous curvature. However, the surface function can include high-order terms in order to provide optical properties that functionally approximate an intraocular lens having discrete optical zones.

In various embodiments, an intraocular lens can include regions in addition to the first and second regions that have nonzero relative powers respect to the base power of the lens. In one example, a first region can include a range of relative powers for providing near vision in a patient with presbyopia, and a second region can include a range of relative powers for correcting intermediate vision in the same patient. The first and second regions can be positioned in a radially symmetric manner about an optical axis, with the third region being positioned around the first and second regions. The third region, which can be defined by the same surface function which defines the first and second regions, can define the base power of the lens (i.e. have an relative power of approximately zero) throughout substantially all of the zone while exhibiting aspheric curvature configured to match the elevations of the second region, such that the second and third regions merge smoothly. Elevations resulting from merging the first, second and third zones are determined, and then fitted to a unique aspheric surface. The continuous aspheric surface approximates some attributes of the original zones, but results in a continuous surface that prevents or mitigates dysphotopsia and optical effects that would ordinarily result from connecting discrete optical zones. In some other embodiments, multiple intermediate regions having different optical power ranges can be provided between the center of an intraocular lens and its periphery.

Exemplary Intraocular Lens Shapes Approximating 2-Zone Surface:

Turning now to the drawings,FIG.1illustrates a multizonal surface102and an analogous, continuous power progressive intraocular lens surface104based on the multizonal surface in a front view, in accordance with embodiments. The multizonal surface102includes two concentric lens surfaces defining a first zone108that is concentric and radially symmetric about an optical axis122, and a second zone112that is concentric with the first zone and also radially symmetric about the optical axis. The original, multizonal surface can be described according to the following dimensions in Table 1:

TABLE 1Lens parameters of an exemplary multizonal lens.Zone 1 (spherical)Zone 2 (aspheric)ExtensionExtensionRelative power(diameter)Relative power(diameter)2.3 D1 mm0 D5 mm

Each zone can be defined according to the aspheric equation for lens sag, as follows:

High-order⁢aspheric⁢equation⁢for⁢an⁢intraocular⁢lens.Z=cr21+1-(k+1)⁢c2⁢r2+a2⁢r2+a4⁢r4+a6⁢r6+a8⁢r8+a10⁢r10+a12⁢r12+z0Equation⁢1

In the equation above ‘r’ is the radial distance in mm, ‘c’ is the curvature in mm−1, ‘k’ is the conic constant, and a2, a4, a6, a8, am, a12are aspheric coefficients; and z0is an elevation parameter referring to an elevation of the aspheric surface. The elevation parameters of two or more surfaces may be adjusted without changing the shapes of the surfaces to smoothly merge both zones, such that an elevation step that may be present between the two zones is eliminated. This parameter directly depends on the geometry of both zones at the inner diameter of the second zone. In embodiments, each zone may be described as an even asphere, such that the zones are radially symmetric.

Each of the zones in the discontinuous multizonal surface102can be defined individually according to the coefficients of the lens equation above. For example, a spherical surface (e.g. zone 1) can be defined where all of the coefficients of the equation, except the curvature, are zero, and the aspheric surface can be defined where a number of the coefficients are nonzero. By way of example, the multizonal lens surface102can be described according to the coefficients of Table 2 below.

TABLE 2Exemplary geometry of a multizonal lens surface.Relative powerdiameterrka4a6a8a10a12Zone 12.3 D1 mm9.7000000Zone 20 D5 mm11.6−1.0−7.3E−04−9.3E−04000

The radius of the first zone (R) can be related to the relative power (RP) according the equation 2, below, where Rpostis the radius of the posterior surface, d is the central thickness of the lens, Pbasethe base power and nLand nmare the refractive index of the lens and the media, respectively. The radius of the second zone can be calculated so that in combination with that of the posterior surface, thickness and refractive index of the lens and surrounding media provide with the base power as defined in Table 2.

Equation⁢for⁢determining⁢radius⁢of⁢curvatureas⁢a⁢function⁢of⁢the⁢relative⁢power⁢(RP)R=1000nL⁢Rpost(1000Rpost+Pbase+RPnL-n⁢m)⁢(nL⁢Rpost+(nL-n⁢m)⁢d)Equation⁢2

Alternatively, the radius of the first zone can be calculated from the relative power (RP) and the radius of the second zone (Rz) from Equation 3, below:

Determining⁢the⁢radius⁢of⁢the⁢first⁢zone.R=10001000Rz+RPnL-nmEquation⁢3

The continuous power progressive lens surface104, unlike the multizonal surface102, is defined by a single aspheric equation that is configured to approximate elevations of the multizonal surface and can be described by Equation 1. Although the multizonal surface can be derived by merging the edges of the first and second zones (e.g., by matching an elevation of the outer perimeter of Zone 1 with an inner perimeter of Zone 2) so that a height profile is continuous from the central or optical axis of the lens to the outer periphery, the slope of the multizonal lens is not continuous, which causes the power profile to have a sharp discontinuity as well.

Table 3, below, describes the geometry of the exemplary continuous power progressive lens surface based on the multizonal lens surface described in Table 2, once fitted to a unique aspheric surface defining a continuous progressive lens surface.

TABLE 3Geometry of an exemplary continuous power progressive lens surface.rka4a6a8a10a129.71.8E+00−1E−026E−03−2E−032E−04−1E−05

InFIG.1, the multizonal lens102includes a first zone108defined by the first zone outer perimeter106, and a second zone112, which is defined between the first zone outer perimeter106and the lens periphery110. In some cases, as illustrated in this example, the first zone108may be a spherical surface having a constant optical power from the center122of the lens102to the first zone outer perimeter106. The second zone112can be an aspheric surface having a gradual change in the optical power from the first zone outer perimeter106to the lens periphery110.

The structure of the continuous power progressive lens surface104differs from the multizonal surface102as follows, in accordance with embodiments. Instead of a stark boundary between first and second zones, a first region116blends continuously into a second region120. A region boundary114is eliminated and the slope of the lens surface from the first region116to the second region120changes gradually over radial distance from the center124of the continuous power progressive lens surface104to the periphery118. However, the aspheric equation defining the continuous power progressive lens surface104can approximate multiple optical regimes across the surface. For example, the first region116can approximate attributes of the spherical first zone108, e.g. by providing an equivalent optical power across at least part of the first region116. The second region120can likewise provide an optical power across at least a portion of the second region that is approximately equivalent to an optical power of the second zone112.

FIG.2shows an elevation profile206of the continuous power progressive lens surface104overlaid on the elevation profile of the multizonal lens102(FIG.1), in accordance with embodiments. The continuous power progressive lens surface104appears similar to the multizonal lens102with subtle differences that are more readily visible by mapping the elevation difference306between the two lens surfaces, as shown inFIG.3. The continuous power progressive lens surface104closely approximates the multizonal lens102where the elevation difference is zero, e.g., at a radial distance of zero (the lens center), and is most different from the multizonal lens near a first boundary202between the first and second zones, e.g. at a radial distance of 0.5 mm, where the smooth geometry of the continuous power progressive lens surface104differs from the discontinuous slope of the multizonal lens102, and at an outer periphery204.

Although the elevation differences between the multizonal surface102and the analogous continuous progressive lens surface104(FIG.1) are subtle, the effects of the different elevation profiles may be more readily understood by referring to a comparison between the power profiles of the lenses.

FIG.4illustrates the multizonal power profile408of the multizonal surface102and the analogous continuous progressive power profile406of the continuous progressive lens surface104shown inFIG.1. The multizonal surface (2-zones) is characterized by a constant optical power of greater than 22 diopters in Zone 1 from a radial distance of 0 with respect to the optical axis of the intraocular lens to a radial distance of 0.5 mm, which defines the outer perimeter202of the first zone. The optical power is discontinuous at the radial distance of 0.5 mm, and thereafter follows a diminishing power profile according to the aspheric surface of Zone 2. In the continuous progressive lens surface (asphere), the optical power at the lens center is approximately equal to the power of Zone 1. The power profile of the continuous progressive lens surface406(asphere) decreases without a discontinuity to approximate the optical power of Zone 2.

FIG.5illustrates the difference in power profiles506between the multizonal surface102and the analogous continuous progressive lens surface104(FIG.1) as shown inFIG.4, in greater detail. The power profiles are most closely matched at the lens center (radial distance=0) and in a majority of the second region120(FIG.1), with the greatest difference in power profiles near the power profile discontinuity at the first zone boundary202.

By way of further example,FIG.6illustrates the power profile difference of a power progressive aspheric lens606and the 2-zonal surface608, normalized with respect to a power profile of a standard aspheric monofocal surface. The 2-zonal lens power profile608and aspheric power progressive lens power profile606relate, respectively, to the 2-zone lens surface102and the analogous continuous progressive lens surface104shown inFIG.1.FIG.6illustrates that the power profile of the continuous progressive lens surface differs from both a standard, monofocal aspheric profile and from a multizonal surface102.

In various embodiments, the size of a central region of a continuous progressive lens surface can be increased, obtaining similar results to increasing the size of a central zone of a multizonal surface. For example, Table 4 below illustrates two different designs that have two zones, similar to the multizonal surface102(FIG.1).

TABLE 4Lens parameters of example lens surfaces A1 and A2Zone 1 (spherical)Zone 2 (aspheric)LensRelativeExtensionRelativeExtensionDesignpower(diameter)power(diameter)A11.75 D1.5 mm0 DRest of lensA21.75 D1.3 mm0 DRest of lens

In lens designs A1 and A2 referenced above in Table 4, the central zone (Zone 1) is spherical and the peripheral zone (Zone 2) is aspheric. Zone 1 and 2 of designs A1 and A2 have the same geometry (same maximum relative power in the central zone (−1.75 D) and same base power in the peripheral zone (0 D)). However, the central zone has different extension (either 1.3 mm or 1.5 mm diameter). Table 5, below, describes the geometry of each zone for both designs, in terms of curvature and higher order aspheric terms. It should be noted that although both designs are based on the same geometrical parameters for defining the two zones (Table 5), the final designs differ (Table 6) because of the differences in the size of the central zone.

TABLE 5Lens parameters of example lens surfaces A1 and A2rka4a6a8a10a12A1Zone 110.10.0E+000E+000E+000E+000E+000E+00Zone 211.71.1E+00−7E−04−1E−050E+000E+000E+00A2Zone 110.10.0E+000E+000E+000E+000E+000E+00Zone 211.61.1E+00−7E−04−1E−040E+000E+000E+00

Table 6, below, describes the geometry of both designs A1 and A2 once fitted to a unique aspheric surface defining a continuous progressive lens surface.

TABLE 6Geometry of the fitted aspheric surfacesgenerated from lenses A1 and A2rka4a6a8a10a12A19.96.5E−03−4E−03−1E−034E−04−9E−056E−06A210.0−6.0E−04−5E−031E−036E−05−4E−053E−06

Varying the extension of the central region as described above before generating the continuous progressive lens surface can change the performance of the lens. For example, adjusting the extension of the central region can change the defocus performance of the lens.

By way of example,FIGS.7A-Billustrate the simulated visual acuity of lenses A1706and A2704, with an exemplary monofocal aspheric lens702for comparison purposes, for 3 mm and 5 mm pupil sizes respectively. Visual acuity is calculated according to methods described in U.S. patent application Ser. No. 14/878,294 entitled, “Apparatus, Systems and Methods for Improving Visual Outcomes for Psuedophakic Patient,” which is hereby incorporated by reference.FIG.7Ashows the simulated visual acuity (VA) of the example lenses for a pupil size of 3 mm, andFIG.7Bshows the simulated VA of the example lenses for a pupil size of 5 mm.

FIGS.7A-7Bdemonstrate that adding the central region (the region of the continuous progressive lens surface derived from Zone 1 of the multizonal surfaces) increases depth of focus. In particular, the depth of focus is increased over the monofocal model, as shown by the increased depth of focus of the continuous progressive lens curves706,704(for A1 and A2, respectively) over the monofocal depth of focus curve702for the exemplary monofocal surface (FIGS.7A,7B). For the lens designs ofFIGS.7A-7Bthe depth of focus is increased with respect to that of the monofocal aspheric lens. The impact of the central zone size is also more readily apparent for the smaller pupil than for the larger pupil.FIGS.7A-7Bdemonstrate that the best focus (defocus position with the best visual acuity) of the progressive lens A1 and A2 does not change with the pupil size.

Performance can also be modified by changing the asphericity of the continuous progressive lens surface near the periphery of the lens in an intraocular lens based on two zones. For example, Tables 6-8, below, illustrate aspects of another example of a multizonal lens surface and a continuous progressive lens surface derived therefrom. Table 7 describes the parameters of the third example surface A3. Table 8 describes the geometry of each zone of a multizonal surface conforming to the parameters of Table 7. As illustrated by Table 8, A3 only differs from A2 in the conic constant and higher order aspheric terms describing the second zone. The second zone of A3 resulted in a surface that induces negative spherical aberration, but does not fully compensate for that of the cornea. Table 9 describes the geometry of an aspheric surface defining a continuous progressive lens surface based on the multizonal surface described in Table 8.

TABLE 7Lens parameters of the third example surface A3Zone 1 (spherical)Zone 2 (aspheric)LensRelativeExtensionRelativeExtensionDesignpower(diameter)power(diameter)A31.75 D1.30 mm0 DRest oflens

TABLE 8Geometry of the multizonal surface of lens A3rka4a6a8a10a12A3Zone 110.10.0E+000E+000E+000E+000E+000E+00Zone 211.61.8E+00−6E−04−1E−050E+000E+000E+00

TABLE 9Geometry of the fitted aspheric surface generated from lens A3rka4a6a8a10a12A39.65.0E−03−1E−025E−03−1E−032E−04−8E−06

FIGS.8A-8Bdemonstrate that changing the asphericity in the periphery does not significantly affect the optical performance (visual acuity) for smaller pupil sizes. Note that, inFIG.8A, the A3 curve802does not differ significantly from the A2 curve704. However, at larger pupil sizes, as shown inFIG.8B, the A3 lens increases the depth of focus over the A2 lens. In particular, the depth of focus is further increased over the monofocal model, as shown by the increased depth of focus of the A3 lens curve802over the monofocal depth of focus curve702for the exemplary monofocal surface. A spherical aberration for the peripheral zone can be selected, and then the peripheral zone can be designed based on the amount of asphericity indicated.

Extended Depth of Focus

Embodiments herein disclosed also relate to lenses having a refractive aspheric profile that provides a continuous power progression to provide an extended depth of focus (EDF). The sag of power progressive designs herein disclosed is described by Equation 1. The power progression can be imposed on the anterior or on the posterior lens surface. Table 10 describes a range of values for the parameters describing power progressive refractive profiles on an anterior lens surface for a base lens power of 20 D. Furthermore, a power progressive surface may be applied to the posterior lens surface instead of, or in addition to, the anterior lens surface.

TABLE 10Range of values for lens sag coefficients describing the powerprogression applied on an anterior side of an ophthalmic lensLowerUpperlimitlimitR−812k−57a4−0.020a6−0.0030.01a8−0.0030.002a10−0.00030.0003a12−1.0E−041.0E−04

By way of example, Table 11 describes the geometry of two progressive in power surfaces that provide EDF.FIG.9is a graphical illustration900that shows the simulated visual acuity imparted by the lenses described in Table 11. As shown, both lenses Example 1 (904) and Example 2 (906) provide high visual acuity compared to a comparative, monofocal aspheric lens902throughout an extended focal depth. This visual acuity data demonstrates that the lenses impart extended depth of focus with respect to a monofocal IOL.

TABLE 11Geometry of the fitted aspheric surfaces of Example Lenses 1 and 2 (FIG. 9)rka4a6a8a10a12Example 19.0E+00−4.8E−03−1.3E−025.8E−03−1.4E−031.7E−04−8.0E−06Example 29.7E+00−5.5E−01−1.2E−025.7E−03−1.4E−031.7E−04−8.1E−06

The range of coefficients described in Table 11 are applicable for refractive power progressive profiles with a base power of 20 D. For any given design aspheric progressive in power design, the full range of IOL powers can be expanded. By way of example, Table 12 shows a range of coefficient values describing an aspheric power progressive surface applied to an anterior side of an ophthalmic lens for a range of base powers between approximately 0 D and 50 D. In specific embodiments, the range of base powers can be between 0 D and 50 D, or preferably between 0 D and 40 D, or more preferably from about 5 D to about 34 D, from about 10 D to 30 D, or from 16 D to 28 D.

TABLE 12Range of values for lens sag coefficients describing a powerprogression applied on an anterior side of an ophthalmic lensLowerUpperlimitlimitR429k−313a4−0.020a600.01a8−0.0030a1000.0003a12−1.0E−040
Exemplary Intraocular Lens Shapes Approximating 3-Zone Surface:

FIG.10illustrates a 3-zone multizonal surface1002and an analogous, continuous power progressive lens surface1004based on the multizonal surface in a front view, in accordance with embodiments. Unlike the two-zone multizonal surface102ofFIG.1, the surface1002includes three concentric lens surfaces defining a first zone1006that is concentric and radially symmetric about an optical axis1012, a second zone1008that is concentric with the first zone and also radially symmetric about the optical axis, and a third zone1010that is concentric with the first and second zones, and radially symmetric about the optical axis. The first and second zones1006,1008meet at a first zone boundary1014. The second and third zones1008,1010meet at a second zone boundary1016. The third zone1010extends to the lens periphery1018.

The continuous power progressive lens surface1004based on the above-described multizonal lens surface is defined by a single aspheric equation based on Equation 1, described above. The continuous power progressive lens surface1004can be described in terms of regions that approximate elevations of the multizonal surface. For example, a first region1020, a second region1024, and a third region1026are concentric about the optical axis1028and radially symmetric. The first, second, and third regions1020,1024,1026can be nominally defined by the first region boundary1030, second region boundary1032, and lens periphery1034. However, and unlike the multizonal surface1002from which the continuous power progressive lens surface is derived, there are no discontinuities in the slope of the elevation profile of the continuous power progressive lens surface between the lens center1028and periphery1034.

Varying Central Zone Relative Power in Three Zones:

Implementing designs based on three or more zones can provide for improved depth of focus at various distances, in accordance with embodiments. For example, Tables 13-15 below describe attributes of designs having three zones or regions. Table 13 describes the parameters of various exemplary three-zone multizonal lens surfaces. Table 14 describes the geometry of each multizonal surface conforming to the parameters of Table 13. Table 15 describes the geometry of each aspheric surface defining a continuous progressive lens surface based on the multizonal surfaces described in Table 14.

TABLE 13Parameters of exemplary 3-zone multizonal lens surfaces.Zone 1Zone 2Zone 3RelativeExtensionRelativeExtensionRelativeExtensionPower(Diameter)Power(Diameter)Power(Diameter)H102.75 D0.75 mm1.751.5 mm0RestI101.75 D0.75 mm0.751.5 mm0RestJ102.25 D0.75 mm1.251.5 mm0Rest

In all cases above, the middle zone has a positive relative power over the peripheral zone (zone 3) different from the base power of the lens, and the central zone (zone 1) has a positive relative power that is one diopter higher than the intermediate zone (zone 2). All zones have the same extension for all the designs, 0.75 mm (diameter) and 1.5 mm for the first and second zones, respectively. As described above for the 2-zone cases, each individual zone can be described according to Equation 1, as described below according to Table 14.

TABLE 14Lens parameters of example lens surfaces H10, I10, J10 before fitting.rka4a6a8a10a12H10zone 19.4000000zone 210.8000000zone 311.61.1−7E−04−1E−05000I10zone 110.1000000zone 210.9000000zone 311.61.1−7.2E−04−1E−05000J10zone 19.7000000zone 210.5000000zone 311.61.1−7E−04−1E−05000

Table 15, below, describes the geometry of power progressive lens surface designs H10, I10, and J10 once fitted to a unique aspheric surface defining a continuous power progressive lens surface.

TABLE 15Geometry of the fitted aspheric surfaces generated for lenses H10, I10, J10.rka4a6a8a10a12H109.04.5E−03−1E−026E−03−1E−032E−04−8E−06I1010.48.9E−03−4E−035E−041E−04−4E−053E−06J109.8−5.1E−03−7E−032E−03−3E−047E−067E−07

Varying the relative power of the central zone and intermediate zone with respect the base power of the peripheral zone can change the performance of the continuous power progressive lens surface resulting of the fitting, as shown inFIGS.11A-11B.

By way of example,FIGS.11A-Billustrate the simulated visual acuity of lenses H10, I10, and J10, with the exemplary monofocal aspheric lens702for comparison purposes, for 3 mm and 5 mm pupil sizes respectively.FIG.11Ashows the simulated visual acuity (VA) of the example lenses for a pupil size of 3 mm, andFIG.11Bshows the simulated VA of the example lenses for a pupil size of 5 mm.

FIGS.11A-11Bdemonstrate that a more positive relative power at the central region increases depth of focus of the continuous power progressive lens surface resulting of the fitting. In particular, the depth of focus is increased over the monofocal model, as shown by the increased depth of focus of the continuous progressive lens curves1102,1104, and1106(for H10, I10, and J10, respectively) over the monofocal depth of focus curve702for the exemplary monofocal surface. The impact of the central zone positive power respect to the basic power is also more readily apparent for the smaller pupil than for the larger pupil. It is also possible to change the behavior of the continuous power progressive lens surface resulting of the fitting by changing the power in the outer zone of the initial multizonal design.

Varying Asphericity in the Periphery:

Changing the asphericity in the periphery can also allow for either increasing the depth of focus for large pupil sizes (i.e. when inducing more positive spherical aberration) or improving distance image quality. For example, Tables 16-17 below describe attributes of designs having three zones or regions, with varying degrees of peripheral asphericity.

Table 16 describes the parameters of exemplary three-zone multizonal lens surfaces with varying peripheral asphericity. The designs are ordered by decreasing spherical aberration at zone 3.

TABLE 16Parameters of 3-zone multizonal lens surfaces with varying spherical aberration.Zone 1Zone 2Zone 3ExtensionRelativeExtensionRelativeExtensionRelative Power(Diameter)Power(Diameter)Power(Diameter)z12H32.75 D0.75 mm1.75 D1.5 mm0rest+0.11H82.75 D0.75 mm1.75 D1.5 mm0rest0H92.75 D0.75 mm1.75 D1.5 mm0rest−0.135H102.75 D0.75 mm1.75 D1.5 mm0rest−0.2H72.75 D0.75 mm1.75 D1.5 mm0rest−0.27

Table 17, below, describes the geometry of the designs of Table 16 once fitted to a unique aspheric surface defining a continuous power progressive lens surface.

TABLE 17Geometry of fitted aspheric surfaces generatedfor lenses H3, H8, H9, H10, and H7rka4a6a8a10a12H39.1−1.3E−02−1E−026E−03−1E−032E−04−8E−06H89.1−1.6E−02−1E−026E−03−1E−032E−04−8E−06H99.1−9.6E−03−1E−026E−03−1E−032E−04−8E−06H109.04.5E−03−1E−026E−03−1E−032E−04−8E−06H79.0−4.8E−03−1E−026E−03−1E−032E−04−8E−06

Changing the asphericity in the periphery of the initial multizonal surface can improve the depth of focus for larger pupils (i.e., by inducing more positive spherical aberration) of the continuous power progressive lens surface resulting of the fitting, and can also improve distance image quality (i.e., by inducing a larger amount of negative spherical aberration).

By way of example,FIGS.12A-Bdemonstrate the effects of changing spherical aberration at the periphery of the initial multizonal surface on the simulated visual acuity of the continuous power progressive lens surface resulting of the fitting described in Tables 16 and 17, along with the exemplary monofocal aspheric lens702for comparison purposes. Note that the H10 curve1102for lens H10 is repeated fromFIGS.11A-B.FIG.12Ashows the simulated visual acuity (VA) of the example lenses for a pupil size of 3 mm, andFIG.12Bshows the simulated VA of the example lenses for a pupil size of 5 mm.

FIGS.12A-12Bdemonstrate that all five continuous power progressive lens surface lenses display an increased depth of focus over the monofocal model, as shown by the increased depth of focus of the continuous progressive lens curves1202,1204,1206,1102, and1208(for H3, H8, H9, H10, and H7, respectively) over the monofocal depth of focus curve702for the exemplary monofocal surface. The impact of changing the asphericity is more readily apparent for the larger pupil than for the smaller pupil, as illustrated by the greater spread between the curves inFIG.12B. Note that the H3 curve1202provides a particularly large depth of focus compared to the lenses with negative or zero perimeter spherical aberration on the initial multizonal zone. Conversely, the H7 curve1208, illustrative of an intraocular lens with a particularly negative spherical aberration, provides a comparatively high distance image quality. By selecting the spherical aberration in the peripheral area, an intraocular lens can be tuned to balance distance visual quality and depth of focus so as to suit a patient with a particular visual need or a lifestyle preference, e.g. a patient who prefers to prioritize distance vision, intermediate vision, or near vision.

FIG.13illustrates the simulated visual acuity of various lenses with respect to the optical power. Exemplary curves shown include a reference aspheric monofocal702, two of the three-region power progressive lens surfaces1202and1208(referring to lens surfaces H3 and H7 described above with reference to Tables 16-17 andFIGS.12A-12B), a 2-region aspheric power progressive lens surface1302, and an exemplary standard diffractive multifocal lens1304.

FIG.13demonstrates improved optical performance of power progressive lenses1202,1208,1302, and a diffractive multifocal lens1304over the monofocal aspheric lens702in terms of depth of focus for a pupil size of 3 mm. Additionally, performance at intermediate distances is improved in the fitted, aspheric power progressive lens surfaces1202,1208, and1302over the multifocal lens1304. The visual acuity at far and intermediate distances for the multifocal lens1304is shown to be significantly lower than the visual acuity for the aspheric multifocal power progressive lenses.

FIGS.14A and14Billustrate the simulated contrast sensitivity at 12 cycles per degree (cpd) for each of the lenses described above with respect toFIG.13, for a 3 mm pupil and 5 mm pupil, respectively.FIG.14Ademonstrates that comparable distance contrast sensitivity is obtained between the example monofocal aspheric lens702and the aspheric power progressive lenses1202,1208,1302, and1304, while the standard diffractive multifocal lens1304provides less contrast sensitivity, for 3 mm pupils.FIG.14Bdemonstrates that the effect of lens selection is greater for large (5 mm) pupil sizes, with the standard diffractive multifocal lens1304providing significantly less contrast sensitivity.

FIGS.15A and15Billustrate the pre-clinical dysphotopsia performance for various lenses.FIG.15Ashows the normalized light intensity exhibited through the example lenses as a function of visual angle. The reference monofocal aspheric lens702exhibits low intensity levels around the main image, while the example standard diffractive multifocal lens1204exhibits relatively high intensity levels for different eccentricities.FIG.15Ashows that three aspheric power progressive lenses1502,1504, and1208(H10 described in Tables 11-12) exhibit similar halo and glare performance (same light intensity distribution at various visual angles) than the monofocal aspheric lens702.FIG.15Bshows the actual images on which the numerical data atFIG.15Aare based, showing intensity measurements of the reference aspheric monofocal lens702and the aspheric power-progressive lens1504. These comparisons demonstrate that the fitted aspheric power-progressive lens designs display significantly reduced dysphotopsia effects compared to traditional multifocal lenses.

Power Progressive Lenses with Extended Depth of Focus (EDF)

Embodiments herein disclosed also relate to lenses having a refractive aspheric profile that provides a continuous power progression to extend depth of focus (EDF) in combination with diffractive profiles. Power progressive refractive profiles can be defined according to Equation 1.

By way of example,FIG.16compares the power profile of a power-progressive, aspheric EDF lens1602to that of a monofocal spherical lens (spherical lens)1604. The power progression of the exemplary lens Example 3 inFIG.1is created by a higher order asphere that is positioned in the posterior IOL optic. The anterior IOL optic is also aspheric and completely compensates for average corneal spherical aberration. The profile is described by Equation 1 in combination with the coefficients of Table 18.

TABLE 18Coefficients describing the power progressive aspheric lenssurface Example 3 as applied in a posterior side of anophthalmic lensRka4a6a8a10a12−12.9−5.3E−012E−02−9E−032E−03−3E−042E−05

FIG.16shows that, while the spherical lens has a continuous power, the higher order aspheric EDF profile determines a smooth power progression from the center to the periphery. Due to the continuity of power progression, there are no zones in the lens. Therefore, the lens appears visually identical to a monofocal IOL when visually inspected. Because the power profile is different at any radial point of the lens surface, the refractive aspheric profile substantially differs from either spherical or zonal power refractive profiles.

FIG.17illustrates visual acuity by way of simulated defocus curves provided by the higher order aspheric profile of Example 3 (1602) and by the comparative example spherical lens1604, whose power profiles have been shown inFIG.16.FIG.17shows that the progressive power profile results in an extended depth of focus as compared to the spherical lens. The simulated visual acuity performance does not exhibit a bimodal performance, indicating that the continuous power profile effectively extends depth of focus.

Table 19 describes a range of values for the parameters of a power progressive refractive profile positioned on the posterior lens surface for a lens with a base power between 18 D and 20 D. These ranges are applicable when the anterior IOL lens surface is also aspheric and compensates for corneal spherical aberration. According to Table 19, a power progressive refractive profile with the features described herein has a posterior radius between about 11 and 18 mm.

TABLE 19Range of values for coefficients describing the power progressiverefractive profile applied to the posterior surface of an IOL for basepowers between 18 D and 20 DLowerUpperlimitlimitR−18−11k−10.1a400.05a6−0.050a800.01a10−0.010a1200.0001

By way of example,FIG.18compares the power profile of a comparative monofocal spherical lens1604to that of two aspheric EDF designs, Example 3 (1602) as described by Table 18 and Example 4 (1606), whose coefficients are provided in Table 20, below.FIG.18shows that both aspheric EDF designs provide a smooth power progression from the center to the periphery, and providing a more pronounced power progression for Example 3 than for Example 4. The coefficients describing both Example 3 and Example 4 are within the range of values shown in Table 19. It should be noted that the smaller in absolute value the radius of the aspheric design, the steeper the power progression, as illustrated by the example provided inFIG.18.

TABLE 20Coefficients describing the power progressive lens surface applied to theposterior side of the lens of Example 4DesignRka4a6a8a10a12Example 4−16.3−8.1E−027E−03−4E−031E−03−1E−047E−06

The ranges of coefficients described in Table 19 are applicable for refractive power profiles with a base power between 18 D and 20 D. For a given aspheric design, the range of base IOL powers can be expanded. It is possible to create the full range of base powers of a given refractive EDF profile with a determined performance. For example, the design1602has a base power between 18 D and 20 D and defines a determined power progression. The same relative power progression can be obtained for different base powers. Table 21 contains the coefficients that define the full range of base IOL powers with the relative power progression that defines the design1604. Table 21 shows the ranges of coefficients describing a power progressive lens surface similar to Example 3 for a range of base powers between approximately 0 D and 50 D, or preferably between 0 D and 40 D, or more preferably from about 5 D to about 34 D, from about 10 D to 30 D, or from 16 D to 28 D. The ranges shown in Table 21 correspond to possible expansions of the power progressive profile of Example 3.

TABLE 21Range of values for coefficients describing a posterior powerprogression profile for different base powersLowerUpperlimitlimitR−30−10k−424a400.05a6−0.050a800.01a10−0.010a1201.0E−04

Alternatively, the higher order aspheric power-progressive lens surface can be imposed on the anterior lens surface while producing the same or similar continuous power progression. Table 22, below, shows the parameters describing continuous power progressive lens surface disposed on an anterior surface of an ophthalmic lens. Example 4a corresponds to the anterior aspheric design, and Example 4 corresponds to the posterior design.FIG.19shows a graphical comparison1900between lens power profiles of Example 4 (1606), Example 4a (1608) and the monofocal spherical reference lens1604.FIG.19illustrates that the power profiles of the posterior asphere Example 4 and its sibling anterior aspheric design Example 4a are virtually identical.

TABLE 22Coefficients describing the power progression applied inthe anterior optic in Example 4aDesignRka4a6a8a10a12Example 4a10.33.0E−03−8E−034E−03−1E−031E−04−7E−06

Table 23, below, describes a range of values for the parameters describing power progression refractive profiles on the anterior lens surface for a lens having a base power between 18 D and 20 D, when the posterior lens surface is spherical. A power progressive refractive profile with the features described herein can have a posterior radius between 7 and 13 mm. Similarly as for the posterior surface, the greater the radius of the anterior aspheric design, the less pronounced the power progression throughout the lens profile.

TABLE 23Range of values for coefficients describing a powerprogression profile applied to an anterior side of a lensLower limitUpper limitR713k−1.50.05a4−0.10.025a6−0.050.025a8−0.0250.01a10−0.0010.001a12−0.00010.0001
Combined Diffractive and Power Progressive Refractive Lenses

Embodiments disclosed herein can provide an extended depth of focus (EDF). In some embodiments, diffractive intraocular lenses described herein can also provide an EDF that results in a range of vision that covers distance, intermediate and/or near visual lengths with a better image quality than presently available multifocal lenses while mitigating certain dysphotopsia effects, such as glare or halo.

Methods of manufacture for lenses and lens profiles as disclosed herein, as well as methods of treatment utilizing said diffractive and refractive power-progressive lenses may include techniques described in, e.g., U.S. Pat. No. 9,335,563, entitled “MULTI-RING LENS, SYSTEMS AND METHODS FOR EXTENDED DEPTH OF FOCUS,” which is hereby incorporated by reference.

Diffractive lenses can make use of a material having a given refractive index and a surface curvature which provide a refractive power. Diffractive lenses affect chromatic aberration. Diffractive lenses have a diffractive profile which confers the lens with a diffractive power or power profile that contributes to the overall depth of focus of the lens. The diffractive profile is typically characterized by a number of diffractive zones. When used for ophthalmic lenses these diffractive zones are typically annular lens zones, or echelettes, spaced about the optical axis of the lens. Each echelette may be defined by an optical zone, a transition zone between the optical zone and an optical zone of an adjacent echelette, and echelette geometry. The echelette geometry includes an inner and outer diameter and a shape or slope of the optical zone, a height or step height, and a shape of the transition zone. The surface area or diameter of the echelettes largely determines the diffractive power(s) of the lens and the step height of the transition between echelettes largely determines the light distribution between the different powers. Together, these echelettes form a diffractive profile. The diffractive profile affects ocular chromatic aberration. Chromatic aberration can be increased or decreased depending on the morphology of the echelettes that compose the diffractive profile. The modification of chromatic aberration can be at distance, intermediate, near and/or the complete range of vision provided by the diffractive profile.

A traditional multifocal diffractive profile on a lens may be used to mitigate presbyopia by providing two or more optical powers, for example, one for near vision and one for far vision. The hybrid diffractive/refractive lenses disclosed herein provide an extended depth of focus across a range of optical powers. The lenses may take the form of an intraocular lens placed within the capsular bag of the eye, replacing the original lens, or placed in front of the natural crystalline lens. The lenses may also be in the form of a contact lens.

In specific embodiments, the refractive profile and diffractive profile may be applied to the same side of the lens (e.g., both on a posterior surface of the lens, or both on an anterior surface of the lens); or may be applied on opposite surfaces (e.g., with the diffractive profile on the posterior surface and the refractive power-progressive profile on the anterior surface).

According to some embodiments, a lens combining a diffractive profile and an aspheric power-progressive profile may have multiple diffractive zones. For example, a central zone of the lens may have one or more echelettes at one step height and one phase delay, with a peripheral zone having one or more other echelettes at a different step height and/or phase delay. According to a specific example (see Table 24, below), the central zone can have three echelettes and the peripheral zone has 6, providing for a total number of 9 echelettes within a lens of about 5 mm diameter. In the example, the step height of the central zone is lower than in the peripheral zone. In an alternative embodiment, the step height of the central zone may be higher than in the peripheral zone. Alternatively, the step height may be the same throughout the lens profile.

According to embodiments, a refractive power progressive and a diffractive profile occupy an entire working area, or optical area, of the lens. The minimum optical area of an IOL has a radius of about 2 mm around the optical axis. In various embodiments, the optical area has a radius from about 2 mm to about 3 mm; or from about 2 mm to about 2.5 mm. In a preferred embodiment, both the refractive profile and the diffractive profile occupy the entire optical area.

FIG.20is a graphical representation illustrating a combined aspheric refractive/diffractive lens profile2000according to some embodiments. The refractive component of the combined profile is a high order asphere that results in a power progressive profile. The diffractive component of the combined profile contains sets of zones, e.g., a central zone2001, and a peripheral zone2003that partially corrects for ocular chromatic aberrations.

The central zone2001in the example profile2000has three echelettes2002having the same, first step heights2005. The peripheral zone2003has six echelettes2004having the same, second step heights2006. The total number of echelettes, and the step heights of the echelettes in each zone, may vary. The central zone2001extends from a lens center2010to a first position2007and the peripheral zone2004extends from the first position2007to a second position2008defined in terms of the radius of the lens. The specific attributes of an example lens D1 (2000) are described below in Table 24:

TABLE 24Diffractive Profile Parameters# ofPhase DelayStep HeightExtension ofD1Echelettes(λ)(μm)the zone (mm)Central Zone31.35.3 (105)1.42Periphery61.3665.6 (106)2.45

The diffractive profile in the example lens D1 has a phase delay between 1 and 2λ for all of the echelettes. This phase delay has the effect of causing the diffractive profile to operate primarily in the first and second diffractive orders. As a consequence, the diffractive design partially corrects ocular chromatic aberration. Phase delay can pertain to a single echelette; or can be ascribed to a group of echelettes each having the same phase delay, where the group comprises a zone of the diffractive profile. Thus, phase delay can characterize single echelettes, groups of echelettes, or an entire profile.

According to various embodiments, the number of diffractive echelettes for a lens configured for a 5 mm pupil may range from 5 to about 14 echelettes. The first echelette boundary can be positioned at a radius of between 0.6 and 1.1 mm, with the remainder of the echelettes placed between the first echelette boundary and the lens periphery. The position of each subsequent echelette after the first echelette can be determined by the position of the first echelette multiplied by the square root of the respective echelette number.

Where the echelettes differ in phase delay between a central zone and a peripheral zone, the central zone can include between 1 and 5 echelettes, or between 1 and 3 echelettes. The phase shift of echelettes in the peripheral zone may be greater than 1λ and smaller than 1.6λ, or between 1.2 and 1.4λ. The phase shift of the echelettes in the central zone may be smaller, greater, or in some cases the same as in the periphery. In some embodiments, the phase shifts of the central echelettes may be 0.1 to 0.5λ, smaller than, or greater than, the phase shifts of echelettes in the periphery. Alternatively, a central echelette or echelettes may have the same phase shift as echelettes in the periphery, while a remainder of the rings in the central zone have a greater or smaller phase shift than the echelettes in the periphery, e.g. by about 0.1 to about 0.5λ.

In alternative embodiments, the phase delay may be between 2 and 3λ. In such an embodiment, the diffractive profile operates between the second and third diffractive order. In such cases, the phase shifts of the peripheral zone should preferably be greater than 2λ, and smaller than 2.6λ, or between 2.2 and 2.4λ. The phase shift of the echelettes in the central zone may be smaller, greater, or in some cases the same as in the periphery. In some embodiments, the phase shifts of the central echelettes may be 0.1 to 0.5λ, smaller than, or greater than, the phase shifts of echelettes in the periphery. Alternatively, a central echelette or echelettes may have the same phase shift as echelettes in the periphery, while a remainder of the rings in the central zone have a greater or smaller phase shift than the echelettes in the periphery, e.g. by about 0.1 to about 0.5λ.

Light distribution is controlled by the step height between zones, such that a portion of the focusable light is directed to a distance focus, with most of the remainder of the light providing the extended depth of focus. The total light efficiency in the range of vision provided by the diffractive profile is approximately 93%. That efficiency results in a light loss of 7%, which is approximately 50% lower than a light loss typical for standard multifocal IOLs (which have light efficiencies of approximately 82%).

According to some embodiments, a hybrid, combined diffractive/power progressive refractive lens includes a combination of a diffractive profile, similar to the diffractive profile described above with reference to Table 24, with a refractive power progressive profile, as described above with reference to, e.g.,FIGS.16-18. Performance of the hybrid or combined designs, as compared to a power-progressive refractive component (Example 3) and as compared to a diffractive ERV component (D1), is shown in the simulated VA curves2100ofFIG.21.

FIG.21shows that the hybrid lens2106formed by a combination of a power-progressive refractive profile2102and diffractive profile2104provides a depth of focus that is larger than the depth of focus achievable with either of the individual refractive or diffractive profiles alone.

In alternative embodiments, different refractive power progressive profiles may be provided for combination with the aforementioned, or other, diffractive profiles. For example, the depth of focus of the combination can be controlled by providing a power progressive profile with a more or less pronounced power progression.

For comparative purposes,FIG.22illustrates the simulated VA curves2200of example lenses and lens components Example 4a (the progressive power lens profile described above at Table 22) and D1 (the diffractive ERV lens profile described above in Table 24) alongside combined lenses utilizing D1 in combination with Example 4a.FIG.22shows that the hybrid combined lens profile2206, which is formed by combining the refractive profile2202and diffractive profile2204, provides a depth of focus that is larger than the depth of focus achievable with either of the individual refractive or diffractive profiles alone. However, the depth of focus of the combination2206is substantially smaller than for the hybrid, combined lens profile2106(FIG.21). The longer depth of focus of the hybrid combined lens profile shown inFIG.22compared to that ofFIG.21is provided by the steeper power progression described of the power progressive lens of Example 3 (FIG.21).

In an alternative embodiment, a lens combining a diffractive profile and an aspheric power-progressive profile may have diffractive echelettes with the same step height. For example,FIG.23is a graphical representation illustrating aspects of the diffractive component of a combined aspheric refractive/diffractive lens profile2300according to some embodiments. The example profile2300has nine echelettes2302having the same step heights2304. In some specific embodiments, the first echelette2302ahas a boundary positioned at about 0.79 mm from the optic center of the lens. However, it will be understood that the position of the first echelette boundary, the total number of echelettes, and the step heights and position of the echelettes, may vary.

According to embodiments, the diffractive profile2300has a consistent phase delay through the optical zone. According to some embodiments, the phase delay is larger than 1λ, and smaller than 2λ, for all the echelettes. This profile provides for a diffractive profile that operates in predominantly in the first and second diffractive orders, so that the lens partially corrects ocular chromatic aberration.

Specific embodiments of combined diffractive/refractive power progressive lenses are described in terms of visual acuity simulations inFIGS.24and25. According to one example, SM-1 is an example diffractive lens profile with a diffractive part that has nine echelettes with common phase delays of 1.366λ and step heights of 5.6 microns as shown below in Table 25. Alternative embodiments are also shown, i.e. SM-3, which is an example diffractive lens profile having a phase delay of 1.5, with step heights of 6.2 mm, respectively. The positions of the diffractive echelettes are the same for all embodiments presented in Table 25.

TABLE 25Diffractive Profile ParametersDiffractivePhase DelayProfile# of Echelettes(λ)Step Height (μm)SM-191.3665.6SM-391.56.2

In some (general) embodiments, phase delay can be larger than 1λ and smaller than 2λ. In specific embodiments, phase delay can range from about 1.1λ up to 1.6λ, or from 1.2 to 1.5λ, The number of echelettes is determined based on the desired geometry of each echelette and the available radius. The number of echelettes may vary from as few as 5 to up to 10 in some specific embodiments; or in certain embodiments up to 14. For example, for a lens configured for a pupil with a diameter of 5 mm, the number of echelettes may range between 5 and 14 echelettes. In specific embodiments, the first echelette may be positioned with an echelette boundary between 0.6 and 1.1 mm from a center of the lens, with a remainder of the echelettes placed according the position of the first echelette multiplied by the square root of the echelette number.

In an alternative embodiment, the phase delays of the diffractive echelettes may be between 2 and 3λ. In such cases, the diffractive profile operates between the second and third diffractive orders. In specific embodiments of lenses with echelettes having phase delays between 2 and 3λ, the ranges for the phase shifts of the echelettes is generally greater than 2λ and smaller than 2.6λ, or preferably between 2.2 and 2.5λ.

A hybrid, combined diffractive/power progressive refractive lens was developed by combining the diffractive profile described above with reference to Table 25 with the refractive power progressive profiles described with reference toFIGS.16-19. Various diffractive profiles can be combined with the refractive power-progressive profile in this manner. For example, specific hybrid, combined diffractive/power progressive refractive lens profiles were developed (the combined profiles) by combining the diffractive profiles described above with reference to Table 25 with one or another of the refractive power progressive profiles described with reference toFIGS.16-18.

For example,FIG.24shows simulated VA curves2400for the SM-1 diffractive profile2404with a comparative, simulated VA curve for a representative power-progressive refractive design (refractive only) power-progressive lens surface, Example 32402. The performance of the combined design2406, which incorporates both profiles SM-1 and Example 3, exhibits a broader range of visual acuity in the near and intermediate visual range (i.e. a longer depth of focus) than either component part.

Combined profiles based on SM-1, and SM-3 each provide for slightly different distributions of light for distance vision n shown in Table 26, below:

TABLE 26Diffractive Profile Light Distribution to Distance Range,and Total Light Efficiency in the Range of VisionDistanceRange of VisionSM-10.620.93SM-30.420.92

In Table 26, the SM-1 diffractive lens profile directs 62% of the focusable light to the distance focal range. The light efficiency in the range of vision provided by the diffractive profile is approximately 93%. That results in a light loss of 7%, which is approximately 50% lower than the light loss for a multifocal IOL operating in a similar range (which has a light efficiency of approximately 82%).

The alternate embodiments, SM-3, exhibit a different light distribution profile. SM-3, provides a greater distribution of light to extended depth of focus range (i.e., an extended range of vision including near and intermediate distances) than SM-1. In all the cases, the light efficiency in the total visual range (distance and extended depth of focus) is larger than that for traditional multifocal lenses.

For a given refractive power-progressive profile, the performance of the combination depends on the diffractive profile. For diffractive profiles with a greater light distribution at the extended depth of focus, near performance is further enhanced when combined with the refractive profile. For example,FIG.25shows simulated VA curves2500for various lenses incorporating the same power-progressive profile (Example 3) with differing diffractive profiles SM-1 (2406), and SM-3 (2506) in accordance with embodiments. For example, the combination diffractive/power progressive refractive lens using the diffractive profile SM-3, which has an increased light distribution to the extended depth of focus range, provides increased performance at the intermediate and near region. In contrast, the combination with SM-1 provides better distance performance but a slightly shorter depth of focus.

Systems and Methods for Determining Lens Shape:

FIG.26is a simplified block diagram illustrating a system2600for generating a continuous progressive lens surface, such as the continuous progressive lens surfaces104ofFIG.1or904(FIG.9), based on a multizonal surface, in accordance with embodiments. The system2600can be used for generating other continuous progressive lens surfaces as well, including lens surfaces configured for providing more than two or three optical regimes. The system2600may, in some cases, be used to generate a multizonal lens surface as an intermediate step to generating a continuous progressive lens surface. The system2600may also be used to produce IOLs conforming to a generated continuous progressive lens surface. In some embodiments, the system2600can be used to produce IOLs including a diffractive profile that is combined with a continuous power-progressive lens surface, either combined on the same surface (anterior or posterior) of the lens, or occupying opposite sides of the continuous progressive lens surface.

The system2600includes a user input module2602configured to receive user input defining aspects of an intraocular lens. Inputs to design an intraocular lens may include a patient's visual needs, corneal aberrations (or corneal topography, from which corneal aberrations can be retrieved), a pupil size performance, and lens dimensions, among other attributes. For example, the input can include a desired optical power profile for correcting impaired distance vision, a desired optical power profile for correcting impaired intermediate distance vision, a desired optical power profile for accommodating near distance vision, and any suitable combination of the above. In some cases, a desired optical power profile may relate to a patient's lifestyle, e.g., whether the patient prefers to participate in activities requiring predominantly distance vision, intermediate vision, or near vision without additional visual correction. A multifocal prescription can be calculated from a patient's visual needs. The multifocal prescription can include, for example, a preferred optical power or optical power profile for correcting far vision and an optical power or optical power profile for near vision. In some cases, a multifocal prescription can further include an optical power or optical power profile for correcting intermediate vision, which may fall between the optical powers or ranges of optical powers described above. The corneal aberrations (or corneal wave front aberrations) can include the higher order rotationally symmetrical aberrations of the cornea as a function of the pupil size. A pupil size performance can include a pupil diameter of a patient and the vision distance to be improved. These parameters can also be related to patient's life style or profession, so that the design incorporates patient's visual needs as a function of the pupil size. In some cases, parameters such as the asphericity of a peripheral region can be determined based on a function of the wave front aberrations and visual needs of the patient. Lens dimensions can include a preferred radius of the total lens, and may further include preferred thickness, or a preferred curvature of one or the other of the anterior surface and posterior surface of the lens.

A surface modeling module2604can receive information about the desired lens from the user input module2604, and can determine aspects of a multizonal lens. According to some embodiments, the surface modeling module2604includes a multizonal surface modeling module2604a, which can determine a multizonal lens profile according to a patient's visual needs. According to some embodiments, the surface modeling module2604can also include a diffractive surface modeling module2604b, which can determine a diffractive lens profile also according to a patient's needs, preferably for combination with a refractive power-progressive profile.

For example, the multizonal surface modeling module2604acan determine the shape of one or more zones of the multizonal lens, such as a curvature profile (e.g. spherical, aspheric) of each zone needed to fulfill the multifocal prescription, and the specific curvature of each zone. The curvature of the outer zone can be related to the biometry of the patient, while the curvature of the intermediate zones can be related with his visual needs in terms of intermediate and near performance. The asphericity of the outer zone can also be related to that of the patient's cornea, so that it either compensates patient's corneal spherical aberration or induces a certain amount of spherical aberration to help improving intermediate and near performance in mesopic conditions. The multizonal surface modeling module2604acan further determine positions of zone boundaries. For example, the multizonal surface modeling module2604acan define an outer diameter of the lens, i.e. the lens periphery, based on desired lens dimensions. The multizonal surface modeling module2604amay further define a boundary between two or more optical zones based on the pupil size, the outer diameter of the lens, or both. In cases where there are more than two zones, the multizonal surface modeling module2604acan define the respective inner and outer radii of each zone based also on the number of zones. The multizonal surface modeling module2604acan also define heights of each respective zone, e.g. to match the heights of adjacent portions of each zone, such that an elevation profile of the lens is continuous.

The multizonal surface modeling module2604acan be configured to generate performance criteria2612, e.g. via modeling optical properties in a virtual environment. Performance criteria can include the match of the optical power profile of the multizonal lens with the desired optical power profile based on the multifocal prescription. The performance criteria can also include the severity of refractive aberrations caused by the multizonal surface. In some cases, the multizonal surface modeling module2604acan provide an intraocular lens surface to an intraocular lens fabrication module for facilitating the production of a physical lens, which can be tested via an intraocular lens testing module2610for empirically determining the performance criteria2612, so as to identify optical aberrations and imperfections not readily discerned via virtual modeling, and to permit iteration.

The multizonal surface modeling module2604acan provide a multizonal surface to a surface generation module2606, which can be configured to produce a smooth aspheric surface such as the continuous power progressive lens surface104(FIG.1). The surface generation module2606can be configured to generate an elevation map of a multizonal lens surface, and can fit an aspheric equation of the form of Equation 1 to the elevation map via any suitable computational method for approximating an empirical dataset. In some cases, the aspheric equation can be fitted via a least-squares fitting method.

According to some embodiments, a diffractive surface modeling module2604bcan operate in tandem with the multizonal surface modeling module2604ato generate a diffractive profile for combination with a refractive power progressive profile, according to the methods disclosed herein. The diffractive surface modeling module2604bcan define a diffractive profile having specific echelette configurations, i.e. echelette numbers, positions, step heights, and phase delays, according to a patient visual need as provided by the user input module2602. By way of nonlimiting example, one such diffractive profile may be an diffractive EDF profile tuned to work in combination with a refractive power progressive profile. Performance criteria2612can be assessed by either or both of the multizonal surface modeling module2604aand the diffractive surface modeling module2604b.

As described above with respect to the surface modeling module2604, the surface generation module2606can also be configured to generate performance criteria2612. Performance criteria can include the match of the optical power profile of a continuous power progressive lens surface generated by the surface generation module2606with the original multizonal surface. The above performance criteria may be weighted over lens regions that are spatially separate from the optical zone step of the original lens. In some cases, the surface generation module2606can also provide a continuous power progressive lens surface to the lens fabrication module2608in order to produce an intraocular lens for testing by the lens testing module2610, so as to identify optical aberrations, visual artifacts and imperfections not readily discerned via virtual modeling, and to permit iteration. Iteration can include modifying parameters of the fitting step (e.g., a degree of fit, a maximum order of terms of the fitting equation, a number and selection of positions chosen for approximating the fit), and can also include iteratively changing parameters of the multizonal surface at the multizonal surface modeling module2604.

FIG.27is an example process2700for generating a continuous power progressive lens surface, in accordance with embodiments. The process2700may be implemented in conjunction with, for example, the system2700shown inFIG.27. Some or all of the process2700(or any other processes described herein, or variations, and/or combinations thereof) may be performed under the control of one or more computer systems configured with executable instructions and may be implemented as code (e.g., executable instructions, one or more computer programs, or one or more applications) executing collectively on one or more processors, by hardware or combinations thereof. The code may be stored on a computer-readable storage medium, for example, in the form of a computer program comprising a plurality of instructions executable by one or more processors. The computer-readable storage medium may be non-transitory.

The process2700includes receiving an input indicative of a patient's visual needs (act2702). The input can include, e.g., a desired optical power profile for correcting impaired distance vision, a desired optical power profile for correcting impaired intermediate vision, a desired optical power profile for accommodating near vision, and any suitable combination of the above. Next, a first optical zone can be defined according to a first optical power profile indicated by the multifocal lens prescription (act2704). For example, the first zone can have a power profile suitable for correcting near and/or intermediate vision (i.e. a high relative power) and can be defined to include the center of the lens and extend to an outer perimeter of the first zone. The diameter defining the outer perimeter of the first zone is sized such that a patient seeing through the lens would see light incident through the first zone as well as light incident from outside the first zone. Next, a second optical zone can be defined according to a second optical power profile also indicated by the multifocal lens prescription (act2706). In some cases, the second optical zone may be related to distance vision (i.e. a power profile for providing distance vision). In some cases, the second optical zone may have an aspheric profile suitable for correcting the corneal spherical aberration.

Next, the first and second optical zones can be merged to form a single multizonal surface (act2708). A diameter defining the first optical zone extends to an interior edge of the second optical zone, and an outer diameter of the second optical zone may extend to a periphery of the lens. However, in some cases, additional optical add zones may be provided beyond the second. Generally, the first and second optical zones are defined as concentric and radially symmetric about the optical axis of the lens, with the second optical zone bounding the first optical zone. The relative heights of the first optical zone and second optical zone are adjusted such that an elevation of the outer perimeter of the first optical zone matches an elevation of the inner perimeter of the second optical zone. If additional zones are included, then each successive outer perimeter can be matched with each successive inner perimeter to generate a continuous elevation profile from the center of the lens to the lens periphery.

The multizonal surface can then be fitted to a new, unique and continuous aspheric surface which approximates attributes of the zones of the multizonal surface (act2710). In some cases, fitting the multizonal surface to the continuous aspheric surface can include generating an elevation map of the multizonal surface, and performing a computational fitting based on a high-order aspherical lens equation like Equation 1, reproduced below, in which various high-order coefficients (e.g. a10, a12) are nonzero.

Z=cr21+1-(k+1)⁢c2⁢r2+a2⁢r2+a4⁢r4+a6⁢r6+a8⁢r8+a10⁢r10+a12⁢r12

However, various other methods of fitting a high-order aspheric equation to the multizonal surface are possible within the scope of this disclosure. The final surface generated by the process2700can be characterized by a continuous function, such that a slope of an elevation map describing the generated surface is also continuous.

Where a purely refractive power-progressive lens is desired (i.e., not a combined diffractive/refractive lens) (act2714), the system can generate instructions to fabricate an intraocular lens based on the generated aspheric surface (act2712). However, in cases where a combined, or hybrid, diffractive/refractive power progressive lens is desired, the system can further define a diffractive lens profile according to the patient's visual needs and for combination with a power progressive profile (act2716). In some cases, the diffractive profile may be defined for addition to a known power progressive profile; but in other cases, the specific diffractive profile and the specific power progressive refractive profile may be generated in an opposite order, or by an iterative process that incrementally adjusts both profiles to achieve the desired visual correction. A combined diffractive/power progressive refractive lens surface can then be generated based on the aspheric power-progressive profile and on the diffractive profile (act2718). This generation can include generating a lens surface that has both the diffractive and refractive power progressive components on the same lens surface (e.g., posterior or anterior surface), or may provide a total lens surface having the respective components positioned on opposite surfaces from each other. The surface features defined by the diffractive profile (e.g., diffractive echelettes) overlap with the features defined by the refractive power-progressive profile (e.g., the aspheric surface). The system can then generate instructions to fabricate an intraocular lens based on the generated combined diffractive/power progressive refractive lens surface (act2720).

Additional Embodiments

In accordance with various embodiments, methods herein disclosed may be applied for generating a wide variety of useful progressive in power refractive lens designs. The aspheric power progressive surface may be applied for the anterior and posterior surface of the lens alternatively. Although several designs are included herein, changes in the specific parameters defining each zone, as well as the number of zones and the degree of spherical aberration may provide lens designs tailored for a variety of uses, e.g. choosing optical performance for specific distances, depths of focus, or other visual needs, in accordance with embodiments.

In accordance with various embodiments, lens surfaces as disclosed herein may be applied to any suitable existing IOL design. Suitable IOL designs can include toric, monofocal, multifocal, extended range of vision, and refractive-diffractive lenses, and combinations thereof. In some cases, with suitable translation to a corresponding optical plane, methods of determining a lens shape can also be applied to corneal refractive procedures. In alternative embodiments, designs herein disclosed may also be applied to any suitable aspheric optical surface, e.g. IOLs, corneal inlays, and corneal onlays.

In various embodiments, diffractive designs can be added to lenses generated according to the techniques described above. Suitable diffractive designs can include designs for controlling chromatic aberration, to generate multifocal effects, and/or to extend depth of focus.

Computational Methods:

FIG.28is a simplified block diagram of an exemplary computing environment2800that may be used by systems for generating the continuous progressive lens surfaces of the present disclosure. Computer system2800typically includes at least one processor2852which may communicate with a number of peripheral devices via a bus subsystem2854. These peripheral devices may include a storage subsystem2856comprising a memory subsystem2858and a file storage subsystem2860, user interface input devices2862, user interface output devices2864, and a network interface subsystem2866. Network interface subsystem2866provides an interface to outside networks2868and/or other devices, such as the lens fabrication module2608or lens testing module2610ofFIG.26. In some cases, some portion of the above-referenced subsystems may be available in a diagnostics device capable of measuring the biometric inputs required for calculating attributes such as base power.

User interface input devices2862may include a keyboard, pointing devices such as a mouse, trackball, touch pad, or graphics tablet, a scanner, foot pedals, a joystick, a touchscreen incorporated into the display, audio input devices such as voice recognition systems, microphones, and other types of input devices. User input devices2862will often be used to download a computer executable code from a tangible storage media embodying any of the methods of the present invention. In general, use of the term “input device” is intended to include a variety of conventional and proprietary devices and ways to input information into computer system2822.

User interface output devices64may include a display subsystem, a printer, a fax machine, or non-visual displays such as audio output devices. The display subsystem may be a cathode ray tube (CRT), a flat-panel device such as a liquid crystal display (LCD), a projection device, or the like. The display subsystem may also provide a non-visual display such as via audio output devices. In general, use of the term “output device” is intended to include a variety20of conventional and proprietary devices and ways to output information from computer system2822to a user.

Storage subsystem2856can store the basic programming and data constructs that provide the functionality of the various embodiments of the present invention. For example, a database and modules implementing the functionality of the methods of the present invention, as described herein, may be stored in storage subsystem2856. These software modules are generally executed by processor2852. In a distributed environment, the software modules may be stored on a plurality of computer systems and executed by processors of the plurality of computer systems. Storage subsystem2856typically comprises memory subsystem2858and file storage subsystem2860. Memory subsystem2858typically includes a number of memories including a main random access memory (RAM)2870for storage of instructions and data during program execution.

Various computational methods discussed above, e.g. with respect to generating a fitted aspheric lens surface based on a multizonal lens surface, may be performed in conjunction with or using a computer or other processor having hardware, software, and/or firmware. The various method steps may be performed by modules, and the modules may comprise any of a wide variety of digital and/or analog data processing hardware and/or software arranged to perform the method steps described herein. The modules optionally comprising data processing hardware adapted to perform one or more of these steps by having appropriate machine programming code associated therewith, the modules for two or more steps (or portions of two or more steps) being integrated into a single processor board or separated into different processor boards in any of a wide variety of integrated and/or distributed processing architectures. These methods and systems will often employ a tangible media embodying machine-readable code with instructions for performing the method steps described above. Suitable tangible media may comprise a memory (including a volatile memory and/or a non-volatile memory), a storage media (such as a magnetic recording on a floppy disk, a hard disk, a tape, or the like; on an optical memory such as a CD, a CD-R/W, a CD-ROM, a DVD, or the like; or any other digital or analog storage media), or the like.

The particulars shown herein are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of various embodiments of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for the fundamental understanding of the invention, the description taken with the drawings and/or examples making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.

The following definitions and explanations are meant and intended to be controlling in any future construction unless clearly and unambiguously modified in the following examples or when application of the meaning renders any construction meaningless or essentially meaningless. In cases where the construction of the term would render it meaningless or essentially meaningless, the definition should be taken from Webster's Dictionary, 3rd Edition or a dictionary known to those of skill in the art, such as the Oxford Dictionary of Biochemistry and Molecular Biology (Ed. Anthony Smith, Oxford University Press, Oxford, 2004).

As used herein and unless otherwise indicated, the terms “a” and “an” are taken to mean “one”, “at least one” or “one or more”. Unless otherwise required by context, singular terms used herein shall include pluralities and plural terms shall include the singular.

Unless the context clearly requires otherwise, throughout the description and the claims, the words ‘comprise’, ‘comprising’, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”. Words using the singular or plural number also include the plural and singular number, respectively. Additionally, the words “herein,” “above,” and “below” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of the application.

The description of embodiments of the disclosure is not intended to be exhaustive or to limit the disclosure to the precise form disclosed. While the specific embodiments of, and examples for, the disclosure are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the disclosure, as those skilled in the relevant art will recognize.

All references, including patent filings (including patents, patent applications, and patent publications), scientific journals, books, treatises, technical references, and other publications and materials discussed in this application, are incorporated herein by reference in their entirety for all purposes.

Aspects of the disclosure can be modified, if necessary, to employ the systems, functions, and concepts of the above references and application to provide yet further embodiments of the disclosure. These and other changes can be made to the disclosure in light of the detailed description.

Specific elements of any foregoing embodiments can be combined or substituted for elements in other embodiments. Furthermore, while advantages associated with certain embodiments of the disclosure have been described in the context of these embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the disclosure.

While the above provides a full and complete disclosure of exemplary embodiments of the present invention, various modifications, alternate constructions and equivalents may be employed as desired. Consequently, although the embodiments have been described in some detail, by way of example and for clarity of understanding, a variety of modifications, changes, and adaptations will be obvious to those of skill in the art. Accordingly, the above description and illustrations should not be construed as limiting the invention, which can be defined by the appended claims.