Patent Description:
Presbyopia is a condition that affects the accommodation properties of the eye. As objects move closer to a young, properly functioning eye, the effects of ciliary muscle contraction and zonular relaxation allow the lens of the eye to change shape, and thus increase its optical power and ability to focus at near distances. This accommodation can allow the eye to focus and refocus between near and far objects.

Presbyopia normally develops as a person ages, and is associated with a natural progressive loss of accommodation. The presbyopic eye often loses the ability to rapidly and easily refocus on objects at varying distances. The effects of presbyopia usually become noticeable after the age of <NUM> years. By the age of <NUM> years, the crystalline lens has often lost almost all elastic properties and has only a limited ability to change shape.

Along with reductions in accommodation of the eye, age may also induce clouding of the lens due to the formation of a cataract. A cataract may form in the hard central nucleus of the lens, in the softer peripheral cortical portion of the lens, or at the back of the lens. Cataracts can be treated by the replacement of the cloudy natural lens with an artificial lens. An artificial lens replaces the natural lens in the eye, with the artificial lens often being referred to as an intraocular lens or "IOL".

Monofocal IOLs are intended to provide vision correction at one distance only, usually the far focus. At the very least, since a monofocal IOL provides vision treatment at only one distance and since the typical correction is for far distance, spectacles are usually needed for good vision at near distances and sometimes for good vision at intermediate distances. The term "near vision" generally corresponds to vision provided when objects are at a distance from the subject eye at equal; or less than <NUM> feet. The term "distant vision" generally corresponds to vision provided when objects are at a distance of at least about <NUM>-<NUM> feet or greater. The term "intermediate vision" corresponds to vision provided when objects are at a distance of about <NUM> feet to about <NUM>-<NUM> feet from the subject eye. Such characterizations of near, intermediate, and far vision correspond to those addressed in<NPL>.

There have been various attempts to address limitations associated with monofocal IOLs. For example, multifocal IOLs have been proposed that deliver, in principle, two foci, one near and one far, optionally with some degree of intermediate focus. Such multifocal, or bifocal, IOLs are intended to provide good vision at two distances, and include both refractive and diffractive multifocal IOLs. In some instances, a multifocal IOL intended to correct vision at two distances may provide a near (add) power of about <NUM> or <NUM> diopters.

<CIT> describes, in an embodiment, a multifocal diffractive profile comprising a first plurality of substantially mono focal diffractive echellettes, and a second plurality of bifocal echellettes in which the second plurality of echellettes are apodized toward the periphery of the lens to provide far vision correction near the edge of the lens.

Multifocal IOLs may, for example, rely on a diffractive optical surface to direct portions of the light energy toward differing focal distances, thereby allowing the patient to clearly see both near and far objects. Multifocal ophthalmic lenses (including contact lenses or the like) have also been proposed for treatment of presbyopia without removal of the natural crystalline lens. Diffractive optical surfaces, either monofocal or multifocal, may also be configured to provide reduced chromatic aberration.

Diffractive monofocal and multifocal lenses can make use of a material having a given refractive index and a surface curvature which provide a refractive power. Diffractive lenses have a diffractive profile which confers the lens with a diffractive power that contributes to the overall optical power of the lens. The diffractive profile is typically characterized by a number of diffractive zones. When used for ophthalmic lenses these 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 an 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.

A multifocal diffractive profile of the 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 lenses may also 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, most commonly a bifocal contact lens, or in any other form mentioned herein.

Although multifocal ophthalmic lenses lead to improved quality of vision for many patients, additional improvements would be beneficial. For example, some pseudophakic patients experience undesirable visual effects (dysphotopsia), e.g. glare or halos. Halos may arise when light from the unused focal image creates an out-of-focus image that is superimposed on the used focal image. For example, if light from a distant point source is imaged onto the retina by the distant focus of a bifocal IOL, the near focus of the IOL will simultaneously superimpose a defocused image on top of the image formed by the distant focus. This defocused image may manifest itself in the form of a ring of light surrounding the in-focus image, and is referred to as a halo. Another area of improvement revolves around the typical bifocality of multifocal lenses. While multifocal ophthalmic lenses typically provide adequate near and far vision, intermediate vision may be compromised.

A lens with an extended range of vision may thus provide certain patients the benefits of good vision at a range of distances, while having reduced or no dysphotopsia. Various techniques for extending the depth of focus of an IOL have been proposed. For example, some approaches are based on a bulls-eye refractive principle, and involve a central zone with a slightly increased power. Other techniques include an asphere or include refractive zones with different refractive zonal powers.

Although certain proposed treatments may provide some benefit to patients in need thereof, further advances would be desirable. For example, it would be desirable to provide improved IOL systems and methods that confer enhanced image quality across a wide and extended range of foci without dysphotopsia. Embodiments of the present invention provide solutions that address the problems described above, and hence provide answers to at least some of these outstanding needs.

Embodiments of the present invention provides an ophthalmic lens according to claim <NUM>, a manufacturing system for making an ophthalmic lens according to claim <NUM>, and a method of designing an intraocular lens according to claim <NUM>.

Embodiments of the invention are illustrated by <FIG>, <FIG>, <FIG> and <FIG>.

<FIG>, <FIG>, <FIG> illustrate multifocal IOL lens geometries, aspects of which are described in <CIT>.

<FIG> is a cross-sectional view of an eye E fit with a multifocal IOL <NUM>. As shown, multifocal IOL <NUM> may, for example, comprise a bifocal IOL. Multifocal IOL <NUM> receives light from at least a portion of cornea <NUM> at the front of eye E and is generally centered about the optical axis of eye E. For ease of reference and clarity, <FIG> do not disclose the refractive properties of other parts of the eye, such as the corneal surfaces. Only the refractive and/or diffractive properties of the multifocal IOL <NUM> are illustrated.

Each major face of lens <NUM>, including the anterior (front) surface and posterior (back) surface, generally has a refractive profile, e.g. biconvex, plano-convex, plano-concave, meniscus, etc. The two surfaces together, in relation to the properties of the surrounding aqueous humor, cornea, and other optical components of the overall optical system, define the effects of the lens <NUM> on the imaging performance by eye E. Conventional, monofocal IOLs have a refractive power based on the refractive index of the material from which the lens is made, and also on the curvature or shape of the front and rear surfaces or faces of the lens. One or more support elements may be configured to secure the lens <NUM> to a patient's eye.

Multifocal lenses may optionally also make special use of the refractive properties of the lens. Such lenses generally include different powers in different regions of the lens so as to mitigate the effects of presbyopia. For example, as shown in <FIG>, a perimeter region of refractive multifocal lens <NUM> may have a power which is suitable for viewing at far viewing distances. The same refractive multifocal lens <NUM> may also include an inner region having a higher surface curvature and a generally higher overall power (sometimes referred to as a positive add power) suitable for viewing at near distances.

Rather than relying entirely on the refractive properties of the lens, multifocal diffractive IOLs or contact lenses can also have a diffractive power, as illustrated by the IOL <NUM> shown in <FIG>. The diffractive power can, for example, comprise positive or negative power, and that diffractive power may be a significant (or even the primary) contributor to the overall optical power of the lens. The diffractive power is conferred by a plurality of concentric diffractive zones which form a diffractive profile. The diffractive profile may either be imposed on the anterior face or posterior face or both.

The diffractive profile of a diffractive multifocal lens directs incoming light into a number of diffraction orders. As light <NUM> enters from the front of the eye, the multifocal lens <NUM> directs light <NUM> to form a far field focus 15a on retina <NUM> for viewing distant objects and a near field focus 15b for viewing objects close to the eye. Depending on the distance from the source of light <NUM>, the focus on retina <NUM> may be the near field focus 15b instead. Typically, far field focus 15a is associated with <NUM>th diffractive order and near field focus 15b is associated with the <NUM>st diffractive order, although other orders may be used as well.

Bifocal ophthalmic lens <NUM> typically distributes the majority of light energy into two viewing orders, often with the goal of splitting imaging light energy about evenly (<NUM>%:<NUM>%), one viewing order corresponding to far vision and one viewing order corresponding to near vision, although typically, some fraction goes to non-viewing orders.

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. The phakic IOL can be placed over the natural crystalline lens or piggy-backed over another IOL. It is also envisioned that the present disclosure may be applied to inlays, onlays, accommodating IOLs, pseudophakic IOLs, other forms of intraocular implants, spectacles, and even laser vision correction.

<FIG> show aspects of a conventional diffractive multifocal lens <NUM>. Multifocal lens <NUM> may have certain optical properties that are generally similar to those of multifocal IOLs <NUM>, <NUM> described above. Multifocal lens <NUM> has an anterior lens face <NUM> and a posterior lens face <NUM> disposed about optical axis <NUM>.

When fitted onto the eye of a subject or patient, the optical axis of lens <NUM> is generally aligned with the optical axis of eye E. The curvature of lens <NUM> gives lens <NUM> an anterior refractive profile and a posterior refractive profile. Although a diffractive profile may also be imposed on either anterior face <NUM> and posterior face <NUM> or both, <FIG> shows posterior face <NUM> with a diffractive profile. The diffractive profile is characterized by a plurality of annular diffractive zones or echelettes <NUM> spaced about optical axis <NUM>. While analytical optics theory generally assumes an infinite number of echelettes, a standard multifocal diffractive IOL typically has at least <NUM> echelettes, and may have over <NUM> echelettes. For the sake of clarity, <FIG> shows only <NUM> echelettes. Typically, an IOL is biconvex, or possibly plano-convex, or convex-concave, although an IOL could be plano-plano, or other refractive surface combinations.

<FIG> are graphical representations of a portion of a typical diffractive profile of a multifocal lens. While the graph shows only <NUM> echelettes, typical diffractive lenses extend to at least <NUM> echelettes to over <NUM> echelettes. In <FIG>, the height <NUM> of the surface relief profile (from a plane perpendicular to the light rays) of each point on the echelette surface is plotted against the square of the radial distance (r<NUM> or ρ) from the optical axis of the lens (referred to as r-squared space). In multifocal lenses, each echelette <NUM> may have a diameter or distance from the optical axis which is often proportional to √n, n being the number of the echelette <NUM> as counted from optical axis <NUM>. Each echelette has a characteristic optical zone <NUM> and transition zone <NUM>. Optical zone <NUM> typically has a shape or downward slope that is parabolic as shown in <FIG>. The slope of each echelette in r-squared space (shown in <FIG>), however, is the same. As for the typical diffractive multifocal lens, as shown here, all echelettes have the same surface area. The area of echelettes <NUM> determines the diffractive power of lens <NUM>, and, as area and radii are correlated, the diffractive power is also related to the radii of the echelettes. The physical offset of the trailing edge of each echelette to the leading edge of the adjacent echelette is the step height. An exemplary step height between adjacent echelettes is marked as reference number <NUM> in <FIG>. The step heights remain the same in r-squared space (<FIG>) and in linear space (<FIG>). The step offset is the height offset of the transition zone from the underlying base curve. An exemplary step offset is marked as reference number <NUM> in <FIG>.

Conventional multifocal diffractive lenses typically provide for near and far vision, neglecting visual performance at intermediate distances. Providing for an extended range of vision can help to improve the visual performance at intermediate distances. In addition, providing for a zero-step height between transition zones may reduce visual artifacts such as halos or glare that may otherwise be visible to a user due to one or more of the boundaries between the optical zones.

<FIG> shows a graphical representation illustrating an embodiment of a diffractive profile <NUM>. The diffractive profile <NUM> may result in a lens having an extended range of vision or a multifocal lens.

The diffractive profile <NUM>, in the form of a sag profile, is shown extending outward from an optical axis <NUM>. The diffractive zones, or echelettes, are shown extending radially outward from the optical axis <NUM>, and would be arranged around the optical axis <NUM> (the other half of the diffractive profile <NUM> is not shown). The diffractive profile <NUM> is shown relative to the Y axis <NUM>, which represents the height or phase shift of the diffractive profile <NUM>. The height is shown in units of micrometers, and may represent the distance from the base curve of the lens. In other embodiments, other units or scalings may be utilized.

The height or phase shift of the diffractive profile <NUM> is shown in relation to the radius on the X axis <NUM> from the optical axis <NUM>. The radius is shown in units of millimeters, although in other embodiments, other units or scalings may be utilized. The diffractive profile <NUM> may extend outward from the optical axis <NUM> for a radius of <NUM> millimeters (diameter of <NUM> millimeters), although in other embodiments the diffractive profile <NUM> may extend for a lesser or greater radius.

The diffractive profile <NUM> includes three sets <NUM>, <NUM>, <NUM> of diffractive zones or echelettes. The three sets include a first set <NUM> positioned at a central zone <NUM> of the lens. The second set <NUM> is positioned at an intermediate zone <NUM> of the lens. The third set <NUM> is positioned at a peripheral zone <NUM> of the lens. In accordance with the invention, the third set <NUM> is repeated in series on the peripheral zone <NUM>.

The first set <NUM> is adjacent the optical axis <NUM>. The first set includes three diffractive zones or echelettes 420a, 420b, 420c. The echelettes 420a, 420b, 420c are connected by transition zones 422a, 422b. The separation between the different echelettes 420a, 420b, 420c, as well as the separation between the echelettes of the other sets <NUM>, <NUM>, is indicated by the dashed step number line <NUM>.

The first set <NUM> has a profile defined by the shape or slope of the echelettes 420a, 420b, 420c, and the step height and step offsets (as discussed previously) at the transition zones 422a, 422b, and the height of the first echelette 420a at the optical axis <NUM>, and the height of the trailing end of echelette 420c at the transition zone <NUM>. The first echelette 420a of the first set <NUM> has a negative slope extending from its leading end to its trailing edge or end at the transition zone 422a. The trailing end has a height corresponding to the step offset at the transition zone 422a. The leading end of the second echelette 420b is separated from the trailing end of the first echelette 420a by the step height corresponding to the transition zone 422a.

The second echelette 420b extends from its leading end to the trailing end at transition zone 422b and has a negative slope. The slope of the second echelette 420b may be different than the slope of the first echelette 420a. The trailing end of the second echelette 420b has a height corresponding to the step offset at the transition zone 422b. The step offset at the transition zone 422b is less than the step offset at the transition zone 422a. The second echelette 420b continuously joins with the third echelette 420c at a zero step height. Thus, there is no step height at the transition zone 422b. The radius of curvature of the profile at the transition zone 422b changes however. The zero step height, in any of the sets of echelettes, may reduce visual artifacts such as halos or glare that may otherwise be visible to a user due to one or more of the boundaries between the optical zones.

The third echelette 420c of the first set <NUM> has a leading end connected to the second echelette 420b at the transition zone 422b. The third echelette 420c has a negative slope, which may be different than the slope of the second echelette 420b and the first echelette 420a. The third echelette 420c extends to its trailing end at the transition zone <NUM> between the first set <NUM> and the second set <NUM>. The third echelette 420c may have a zero step offset at the transition zone <NUM>.

Using the scaling shown in <FIG>, the first set <NUM>, and the central zone <NUM>, may end at the radial distance of about <NUM> millimeters.

The profiles of each of the echelettes 420a, 420b, 420c, are different from each other. The different profiles are due to the differing step heights, step offsets, and slopes of each echelette 420a, 420b, 420c. In r-squared space (discussed previously), the profiles of the echelettes 420a, 420b, 420c, are different from each other, due to the differing step heights, step offsets, and slopes of each echelette 420a, 420b, 420c.

The second set <NUM> of echelettes may be adjacent the first set <NUM> of echelettes. The second set <NUM> includes three diffractive zones or echelettes 428a, 428b, 428c. The echelettes 428a, 428b, 428c are connected by transition zones 430a, 430b.

The second set <NUM> has a profile defined by the shape or slope of the echelettes 428a, 428b, 428c, and the step height and step offsets at the transition zones 430a, 430b, <NUM>, and the height of the trailing end of echelette 428c at the transition zone <NUM>. The first echelette 428a of the second set <NUM> connects to the first set <NUM> at the transition zone <NUM>. The transition zone <NUM> has a step height that is larger than any of the step heights of the first set <NUM>. The first echelette 428a has a negative slope extending from its leading end to its trailing end at the transition zone 430a. The trailing end has a height corresponding to the step offset at the transition zone 430a. The leading end of the second echelette 428b is separated from the trailing end of the first echelette 428a by the step height corresponding to the transition zone 430a. The step height of the transition zone 430a is less than the step height of the transition zone <NUM>.

The second echelette 428b extends from its leading end to the trailing end at transition zone 430b and has a negative slope. The slope of the second echelette 428b may be different than the slope of the first echelette 428a. The trailing end of the second echelette 428b has a height corresponding to the step offset at the transition zone 430b. The step offset at the transition zone 430b is less than the step offset at the transition zone 430a.

The third echelette 428c of the second set <NUM> has a leading end connected to the second echelette 428b at the transition zone 430b. The step height of the transition zone 430b may be less than the step height of the transition zones 430a and <NUM>. The third echelette 428c has a negative slope, which may be different than the slope of the first echelette 428a and the second echelette 428b. The third echelette 428c extends to its trailing end at the transition zone <NUM> between the second set <NUM> and the third set <NUM>. The third echelette 428c may have a zero step offset at the transition zone <NUM>. A non-zero step height may be between each of the echelettes of the second set <NUM>.

Using the scaling shown in <FIG>, the second set <NUM>, and the intermediate zone <NUM>, may end at the radial distance of about <NUM> millimeters.

The profiles of each of the echelettes 428a, 428b, 428c, are different from each other. The different profiles are due to the differing step heights, step offsets, and slopes of each echelette 428a, 428b, 428c. In r-squared space, the profiles of the echelettes 428a, 428b, 428c, are different from each other, due to the differing step heights, step offsets, and slopes of each echelette 428a, 428b, 428c.

The profile of the second set <NUM> is different than the profile of the first set <NUM>. The different profiles are due to the differing step heights, step offsets, and slopes of the echelettes within the respective set <NUM>, <NUM>. In r-squared space, the profile of the second set <NUM> is different than the profile of the first set <NUM> due to the differing step heights, step offsets, and slopes of the echelettes within the respective set <NUM>, <NUM>.

The third set <NUM> of echelettes may be adjacent the second set <NUM> of echelettes. The third set <NUM> includes three diffractive zones or echelettes 434a, 434b, 434c. The echelettes 434a, 434b, 434c are connected by transition zones 436a, 436b.

The third set <NUM> has a profile defined by the shape or slope of the echelettes 434a, 434b, 434c, and the step height and step offsets at the transition zones 436a, 436b, <NUM>, and the height of the trailing end of echelette 434c at the transition zone to the next adjacent set. The first echelette 434a of the third set <NUM> connects to the second set <NUM> at the transition zone <NUM>. The transition zone <NUM> has a step height that is smaller than the step height of the transition zone <NUM> and larger than the step heights of the transition zones 422a, 430a, 430b. The first echelette 434a has a negative slope extending from its leading end to its trailing end at the transition zone 436a. The trailing end has a height corresponding to the step offset at the transition zone 436a. The step offset at the transition zone 436a is smaller than the step offsets of any of the first set <NUM> or second set <NUM>.

The leading end of the second echelette 434b is separated from the trailing end of the first echelette 434a by the step height corresponding to the transition zone 436a. The step height of the transition zone 436a is less than the step height of the transition zone <NUM> and greater than the step height of the transition zones 422a, 430a, 430b.

The second echelette 434b extends from its leading end to the trailing end at transition zone 436b and has a negative slope. The slope of the second echelette 434b may be different than the slope of the first echelette 434a. The trailing end of the second echelette 434b has a height corresponding to the step offset at the transition zone 436b. The step offset at the transition zone 436b is greater than the step offset at the transition zone 436a and transition zones 422b and 430b.

The third echelette 434c continuously joins with the second echelette 434b at a zero step height. Thus, there is no step height at the transition zone 436b. The radius of curvature of the profile at the transition zone 436b changes however.

The third echelette 434c of the third set <NUM> has a leading end connected to the second echelette 434b at the transition zone 436b. The third echelette 434c has a negative slope, which may be different than the slope of the second echelette 436b and the first echelette 434a. The third echelette 436c extends to its trailing end at the trailing end of the third set <NUM>, and may have a zero step offset at the trailing end of the third set <NUM>.

The profiles of each of the echelettes 434a, 434b, 434c, are different from each other. The different profiles are due to the differing step heights, step offsets, and slopes of each echelette 434a, 434b, 434c. In r-squared space, the profiles of the echelettes 434a, 434b, 434c, are different from each other, due to the differing step heights, step offsets, and slopes of each echelette 434a, 434b, 434c.

The profile of the third set <NUM> is different than the profile of the first set <NUM> and the profile of the second set <NUM>. The different profiles are due to the differing step heights, step offsets, and slopes of the echelettes within the respective set <NUM>, <NUM>, <NUM>. In r-squared space, the profile of the third set <NUM> is different than the profile of the first set <NUM> and the second set <NUM> due to the differing step heights, step offsets, and slopes of the echelettes within the respective set <NUM>, <NUM>, <NUM>.

In accordance with the invention, the third set <NUM> is repeated in series on the peripheral zone <NUM> to form a repeated set <NUM>. The repeated third set <NUM> may be scaled in radial size relative to the r-squared distance from the optical axis <NUM>, as is known in the art. Thus, the step heights and step offsets of each set in the repeated set will remain the same, as well as the surface area of each echelette of the set. The slope of the echelettes of each set in the repeated set will remain the same in r-squared space. As such, the profile of each repeated third set <NUM> remains the same in r-squared space.

The repeated set <NUM> may include a series of eight third sets <NUM>, as shown in <FIG>. In other embodiments, greater or fewer numbers of third sets <NUM> may be utilized in the repeated set <NUM>. In one embodiment, the repeated set <NUM> may span the entirety of the remaining portion of the lens such that the entirety of the remaining optical zone is filled (may extend out to a full <NUM> millimeter diameter). In other embodiments, the repeated set <NUM> may span only a portion of the lens.

The profile of each of the first nine echelettes 420a, 420b, 420c, 428a, 428b, 428c, 434a, 434b, 434c, of the diffractive profile <NUM>, have different profiles from each other. The different profiles are due to the differing step heights, step offsets, and slopes of each of the first nine echelettes. In r-squared space, the profile of each of the first nine echelettes 420a, 420b, 420c, 428a, 428b, 428c, 434a, 434b, 434c are different from each other due to the differing step heights, step offsets, and slopes of each of the echelettes.

The surface area of the first echelette (420a, 428a, 434a) of each of the respective first, second, and third sets (<NUM>, <NUM>, <NUM>) is the same. The surface area of the second echelette (420b, 428b, 434b) of each of the respective first, second, and third sets (<NUM>, <NUM>, <NUM>) is the same. The surface area of the third echelette (420c, 428c, 434c) of each of the respective first, second, and third sets (<NUM>, <NUM>, <NUM>) is the same. As is apparent from <FIG>, however the step heights and step offsets of the echelettes in the sets (<NUM>, <NUM>, <NUM>) differ. All echelettes shown in <FIG> have the same surface area.

The three echelettes 420a, 420b, 420c of the first set <NUM> do not repeat. If the echelettes 420a, 420b, 420c of the first set <NUM> were to repeat, then the optical characteristics may be defined by at least four diffractive orders corresponding to at least four diffractive powers. The repeated first set <NUM> may produce four diffractive orders that are useful for a patient's vision, corresponding to four diffractive powers that are useful for a patient's vision. The diffractive orders may include a <NUM>th order and orders <NUM>st through <NUM>th. The orders <NUM>nd through <NUM>th may be useful for a patient's vision. The <NUM>th and <NUM>st orders may be hyperopic (beyond far), and the <NUM>th, <NUM>th, and <NUM>th, may be on the myopic side.

If the first set <NUM> were to repeat, the repeated first set <NUM> may distribute light to diffractive orders, with the following light distribution of incident light to each of the four diffractive orders, and the diffractive power shown in Table <NUM> below:.

The three echelettes 428a, 428b, 428c of the second set <NUM> do not repeat. If the echelettes 428a, 428b, 428c of the second set <NUM> were to repeat, then the optical characteristics may be defined by at least four diffractive orders corresponding to at least four diffractive powers. The repeated second set <NUM> may produce four diffractive orders that are useful for a patient's vision, corresponding to four diffractive powers that are useful for a patient's vision. The diffractive orders may include a <NUM>th order and orders <NUM>st through <NUM>th. The orders <NUM>nd through <NUM>th may be useful for a patient's vision. The <NUM>th and <NUM>st orders may be hyperopic (beyond far), and the <NUM>th, <NUM>th, and <NUM>th, may be on the myopic side.

If the second set <NUM> were to repeat, the repeated second set <NUM> may distribute light to four diffractive orders, with the following light distribution of incident light to each of the four diffractive orders, and the diffractive power shown in Table <NUM> below:.

As noted in Table <NUM>, the light distribution to the <NUM>rd and <NUM>th diffractive order is relatively low, such that a repeated second set <NUM> may be considered to operate similar to a bifocal diffractive profile.

The three echelettes 434a, 434b, 434c of the third set <NUM> do repeat. The optical characteristics of the repeated set <NUM> may be defined by at least four diffractive orders corresponding to at least four diffractive powers. The repeated set <NUM> may produce four diffractive orders that are useful for a patient's vision, corresponding to four diffractive powers that are useful for a patient's vision. The diffractive orders may include a <NUM>th order and orders <NUM>st through <NUM>th. The orders <NUM>nd through <NUM>th may be useful for a patient's vision. The <NUM>th and <NUM>st orders may be hyperopic (beyond far), and the <NUM>th, <NUM>th, and <NUM>th, may be on the myopic side.

The repeated set <NUM> may distribute light to four diffractive orders, with the following light distribution of incident light to each of the four diffractive orders, and the diffractive power shown in Table <NUM> below:.

As noted in Table <NUM>, the light distribution to the <NUM>rd and <NUM>th diffractive order is relatively low, such that the repeated set <NUM> may be considered to operate similar to a bifocal diffractive profile. In accordance with the invention, the light distribution of the repeated set <NUM> includes more than <NUM>% of incident light distributed toward a first diffractive power, less than <NUM>% of incident light distributed toward a second diffractive power, less than <NUM>% of incident light distributed toward a third diffractive power, and more than <NUM>% of incident light distributed toward a fourth diffractive power. The second diffractive power may be between about <NUM> and <NUM> diopter, the third diffractive power may be between about <NUM> and <NUM> diopter, and the fourth diffractive power may be between about <NUM> and <NUM> diopter.

The diffractive powers and light distributions listed in each of Tables <NUM>, <NUM>, and <NUM> may vary to an amount that is "about" the listed amount. In other embodiments, the diffractive orders, powers and light distributions, listed in each of Tables <NUM>, <NUM>, and <NUM> may be varied as desired.

The diffractive powers of the lens may vary, depending on the desired performance of the design. The diffractive powers as listed in Tables <NUM>-<NUM> are intended for a design that provides adequate visual performance over the entire range of vision from far to intermediate distances and near. Lower diffractive powers may be beneficial if the desired performance is to emphasize good far and intermediate vision, while vision at near distances may be slightly reduced. Such lens design may have a second diffractive add power of <NUM>. 58D, a third diffractive add power of <NUM>. 17D and a fourth diffractive add power of <NUM>. Some embodiments have diffractive add powers in-between these and those in Tables <NUM>-<NUM>.

The combination of the non-repeating first set <NUM>, second set <NUM>, and the repeated set <NUM>, may result in a diffractive profile producing an extended range of vision for the patient.

In one embodiment, the diffractive profile <NUM> may be positioned on a surface of a lens that is opposite an aspheric surface. The aspheric surface on the opposite side of the lens may be designed to reduce corneal spherical aberration of the patient.

In one embodiment, one or both surfaces of the lens may be aspherical, or include a refractive surface designed to extend the depth of focus, or create multifocality.

In one embodiment, a refractive zone on one or both surfaces of the lens may be utilized that may be the same size or different in size as one of the diffractive zones. The refractive zone includes a refractive surface designed to extend the depth of focus, or create multifocality.

<FIG> shows a graphical representation illustrating an embodiment of a diffractive profile <NUM> not defined by the appended claims. The diffractive profile <NUM> may result in a lens having an extended range of vision or a multifocal lens.

The diffractive profile <NUM> is configured similarly as the diffractive profile <NUM> shown in <FIG>. However, the diffractive profile <NUM> includes a second set <NUM> of echelettes in an intermediate zone <NUM> that has a profile in r-squared space that is substantially identical to the profile of a first set <NUM> of echelettes in r-squared space.

Similar to the diffractive profile <NUM> shown in <FIG>, the diffractive profile <NUM> is shown extending outward from an optical axis <NUM>. The diffractive profile <NUM> is shown relative to the Y axis <NUM>, which represents the height or phase shift of the diffractive profile <NUM>, and is shown in units of micrometers, and may represent the distance from the base curve of the lens.

The height or phase shift of the diffractive profile <NUM> is shown in relation to the radius on the X axis <NUM> from the optical axis <NUM>.

The diffractive profile <NUM> includes three sets <NUM>, <NUM>, <NUM> of diffractive zones or echelettes. The three sets include a first set <NUM> positioned at a central zone <NUM> of the lens. The second set <NUM> is positioned at an intermediate zone <NUM> of the lens. The third set <NUM> is positioned at a peripheral zone <NUM> of the lens. The third set <NUM> may be repeated in series on the peripheral zone <NUM>.

The first set <NUM> may include three diffractive zones or echelettes 520a, 520b, 520c, which may be connected by transition zones 522a, 522b. The separation between the different echelettes 520a, 520b, 520c, as well as the separation between the echelettes of the other sets <NUM>, <NUM>, is indicated by the dashed step number line <NUM>. The reference number <NUM> represents the step offset at the transition zone 522a.

The profile of the first set <NUM> may be the same as the profile of the first set <NUM> shown in <FIG>. The properties of the first set <NUM> may be the same as the properties of the first set <NUM> shown in <FIG>.

The second set <NUM> may include three diffractive zones or echelettes 528a, 528b, 528c, which may be connected by transition zones 530a, 530b. The second set <NUM> may be adjacent to the first set <NUM> and may be connected to the first set <NUM> with transition zone <NUM>. The profile of the second set <NUM> in r-squared space is substantially identical to the profile of a first set <NUM> of echelettes in r-squared space. The step heights and offsets at transition zones 530a and 530b may be the substantially identical to those of respective transition zones 522a and 522b, and the slopes of the echelettes 528a, 528b, 528c may be substantially identical to those of the echelettes 520a, 520b, 520c.

The third set <NUM> may include three diffractive zones or echelettes 534a, 534b, 534c, which may be connected by transition zones 536a, 536b. The third set <NUM> may be adjacent the second set <NUM> and may be connected to the second set <NUM> with transition zone <NUM>.

The profile of the third set <NUM> may be the same as the profile of the third set <NUM> shown in <FIG>.

The third set <NUM> may be repeated in series on the peripheral zone <NUM> to form a repeated set <NUM>, similar to the repeated third set <NUM> shown in <FIG>. The properties of the third set <NUM> and the repeated set <NUM> may be the same as the respective third set <NUM> and repeated third set <NUM> of <FIG>.

In one embodiment, the second set <NUM> may be excluded, such that only echelettes on a central zone and echelettes on a peripheral zone may be utilized in a diffractive profile. The echelettes on the central zone may be adjacent the echelettes on the peripheral zone.

In one embodiment, a diffractive profile may be configured such that the second set of echelettes in the intermediate zone has a profile that is the same as the second set <NUM> of echelettes shown in <FIG>, and a first set of echelettes in a central zone has a profile in r-squared space that is substantially identical to the profile in r-squared space as the second set <NUM> of echelettes shown in <FIG>.

The diffractive profiles disclosed herein may produce an extended range of vision for the patient.

The embodiments of diffractive profiles disclosed herein may be positioned on a surface of a lens that is opposite an aspheric surface. The aspheric surface on the opposite side of the lens may be designed to reduce corneal spherical aberration of the patient.

The embodiments of diffractive profiles disclosed herein may be utilized with one or both surfaces of the lens that may be aspherical, or include a refractive surface designed to extend the depth of focus, or create multifocality.

The embodiments of diffractive profiles disclosed herein may be utilized with a refractive zone on one or both surfaces of the lens that may be the same size or different in size as one of the diffractive zones. The refractive zone includes a refractive surface designed to extend the depth of focus, or create multifocality.

Any of the embodiments of lens profiles discussed herein may be apodized to produce a desired result. The apodization may result in the step heights and step offsets of the repeated sets being varied according to the apodization. The sets, however, are still considered to be repeating sets over the optic of the lens.

A zero step height may be positioned as desired between adjacent echelettes. For example, either echelette of a set of echelettes (e.g., two of three echelettes of a set), or all echelettes of a set of echelettes may have a zero step height. In one embodiment, adjacent sets of echlettes may have a zero step height.

<FIG> is a simplified block diagram illustrating a system <NUM> for generating an ophthalmic lens based on a user input.

The system <NUM> includes a user input module <NUM> configured to receive user input defining aspects of the user and of a lens. The input may accept an ophthalmic lens prescription for a patient eye. Aspects of a lens may include an extended range of vision prescription, anatomical dimensions like a pupil size performance, and lens dimensions, among other attributes. An extended range of vision 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, an extended range of vision prescription can further include an optical power or optical power profile for correcting intermediate vision at two, or in some cases more than two intermediate foci, which may fall between the optical powers or ranges of optical powers described above. A pupil size performance can include a pupil radius of a patient and the visual field to be optimized. 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. 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 multizonal diffractive surface modeling module <NUM> can receive information about the desired lens from the user input module <NUM>, and can determine aspects of a multizonal lens. The multizonal diffractive surface modeling module <NUM> may generate a diffractive profile based on the ophthalmic lens prescription. For example, the modeling module <NUM> can determine the shape of one or more echelettes of the diffractive profile of a diffractive multifocal lens, including the positioning, width, step height, and curvature needed to fulfill the multifocal prescription for each subset of the echelettes, as well as the positioning of each subset of echelettes. The multizonal diffractive surface modeling module <NUM> can further determine the shapes of transition steps between echelettes. For example, transition steps may be smoothed or rounded to help mitigate optical aberrations caused by light passing through an abrupt transition. Such transition zone smoothing, which may be referred to as a low scatter profile, can provide for reductions in dysphotopsia by reducing the errant concentration of incident light behind the lens by the transition zones. By way of further example, echelette ordering, echelette offsets, and echelette boundaries may be adjusted to adjust the step heights between some adjacent echelettes. In particular, the multizonal diffractive surface modeling module can determine echelette offsets to set one or more step heights at echelette transitions to zero, or approximately zero, by these or similar methods. The generated diffractive profile may be any of the diffractive profiles disclosed in this application.

The multizonal diffractive surface modeling module <NUM> can be configured to generate performance criteria <NUM>, 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 extended range of vision prescription. The performance criteria can also include the severity of diffractive aberrations caused by lens surface. In some cases, the multizonal surface modeling module <NUM> can provide a lens surface to a lens fabrication module for facilitating the production of a physical lens, which can be tested via a lens testing module <NUM> for empirically determining the performance criteria <NUM>, so as to identify optical aberrations and imperfections not readily discerned via virtual modeling, and to permit iteration. The lens fabrication module may comprise a manufacturing assembly that may fabricate the ophthalmic lens based on the diffractive profile.

A refractive surface modeling module <NUM> can receive information from the user input <NUM> and multizonal surface modeling modules <NUM> in order to determine refractive aspects of the lens. For example, provided with an extended range of vision prescription and a set of diffractive powers that can be generated by a diffractive profile, the refractive surface modeling module <NUM> can provide a refractive geometry configured to provide a base power which, when combined with the diffractive surface, meets the requirements of the extended range of vision prescription. The refractive surface modeling module <NUM> can also generate performance criteria <NUM>, and can contribute to providing a lens surface to a lens fabrication module <NUM> for facilitating the production of the physical lens.

<FIG> is an example process <NUM> for generating a diffractive lens surface, in accordance with embodiments. The process <NUM> may be implemented in conjunction with, for example, the system <NUM> shown in <FIG>. Some or all of the process <NUM> (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 process <NUM> may include a method of designing an intraocular lens and may include receiving an input of an ophthalmic lens prescription for a patient eye, which may be an extended range of vision lens prescription (act <NUM>). 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 distance vision, a desired optical power profile for accommodating near vision, and any suitable combination of the above. Based on a desired optical power profile, a diffractive profile can be defined and generated including a central zone, a peripheral zone, and an intermediate zone positioned between the central zone and the peripheral zone. The generated diffractive profile may include a central zone including a first set of three echelettes arranged around the optical axis, the first set having a profile in r-squared space (act <NUM>). The generated diffractive profile may include an intermediate zone including a second set of three echelettes arranged around the optical axis, the second set having a profile in r-squared space that is different than the profile of the first set (act <NUM>). The generated diffractive profile may include a peripheral zone including a third set of three echelettes arranged around the optical axis, the third set having a profile in r-squared space that is different than the profile of the first set and the profile of the second set, the third set being repeated in series on the peripheral zone (act <NUM>).

In one embodiment, a diffractive profile may be generated and utilized that includes a central zone and a peripheral zone. The central zone may include a first set of three echelettes arranged around the optical axis, the first set having a profile in r-squared space. The peripheral zone may include a second set of three echelettes arranged around the optical axis, the second set having a profile in r-squared space that is different than the profile of the first set. The second set may be repeated in series on the peripheral zone.

In one embodiment, the diffractive profile may include an intermediate zone positioned between the central zone and the peripheral zone. The intermediate zone may include a third set of three echelettes arranged around the optical axis, the third set having a profile in r-squared spaced that is substantially identical to the profile of the first set (in the central zone).

The diffractive lens profile of the multizonal diffractive lens surface may be used in combination with a known refractive base power. To that end, a refractive lens surface may be generated having a base power that, in combination with the diffractive lens surface generated based on the diffractive profile, meets the extended range of vision lens prescription (act <NUM>). A total lens surface can be generated based on both the refractive lens surface and the diffractive lens surface (act <NUM>). The refractive lens surface can include a refractive lens curvature on the anterior surface of the lens, the posterior surface of the lens, or both. Instructions can be generated to fabricate an intraocular lens based on the generated total lens surface (act <NUM>). A manufacturing assembly may fabricate the ophthalmic lens based on the instructions. The methods herein are not limited to the examples of diffractive profiles discussed here, and may extend to any of the diffractive lens profiles and ophthalmic lenses disclosed in this application.

<FIG> is a simplified block diagram of an exemplary computing environment <NUM> that may be used by systems for generating the diffractive profiles and ophthalmic lenses of the present disclosure. Computer system <NUM> typically includes at least one processor <NUM> which may communicate with a number of peripheral devices via a bus subsystem <NUM>. These peripheral devices may include a storage subsystem <NUM> comprising a memory subsystem <NUM> and a file storage subsystem <NUM>, user interface input devices <NUM>, user interface output devices <NUM>, and a network interface subsystem <NUM>. Network interface subsystem <NUM> provides an interface to outside networks <NUM> and/or other devices, such as the lens fabrication module <NUM> or lens testing module <NUM> of <FIG>.

User interface input devices <NUM> may 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 devices <NUM> will often be used to download a computer executable code from a tangible storage media embodying any of the methods of the present disclosure. 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 system <NUM>.

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 variety of conventional and proprietary devices and ways to output information from computer system <NUM> to a user.

Storage subsystem <NUM> can store the basic programming and data constructs that provide the functionality of the various embodiments of the present disclosure. For example, a database and modules implementing the functionality of the methods of the present disclosure, as described herein, may be stored in storage subsystem <NUM>. These software modules are generally executed by processor <NUM>. 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 subsystem <NUM> typically comprises memory subsystem <NUM> and file storage subsystem <NUM>. Memory subsystem <NUM> typically includes a number of memories including a main random access memory (RAM) <NUM> for storage of instructions and data during program execution and/or a read only member (ROM) <NUM>.

Claim 1:
An ophthalmic lens, comprising:
a first surface and a second surface disposed about an optical axis (<NUM>); and
a diffractive profile (<NUM>) imposed on one of the first surface or the second surface, the diffractive profile including a central zone, a peripheral zone, and an intermediate zone positioned between the central zone and the peripheral zone, wherein:
the central zone (<NUM>) includes a first set (<NUM>) of three echelettes (420a, 420b, 420c) arranged around the optical axis, the first set having a profile in r-squared space;
the intermediate zone (<NUM>) includes a second set (<NUM>) of three echelettes (428a, 428b, 428c) arranged around the optical axis, the second set having a profile in r-squared space that is different than the profile of the first set; and
the peripheral zone (<NUM>) includes a third set (<NUM>) of three echelettes (434a, 434b, 434c) arranged around the optical axis, the third set having a profile in r-squared space that is different than the profile of the first set and the profile of the second set, the third set being repeated in series on the peripheral zone, wherein the third set being repeated in series on the peripheral zone forms a repeated set that is configured to result in a light distribution with more than <NUM>% of incident light distributed toward a first diffractive power, less than <NUM>% of incident light distributed toward a second diffractive power, less than <NUM>% of incident light distributed toward a third diffractive power, and more than <NUM>% of incident light distributed toward a fourth diffractive power,
wherein the second diffractive power is an add power between about <NUM> and <NUM> diopter, the third diffractive power is an add power between about <NUM> and <NUM> diopter, and the fourth diffractive power is an add power between about <NUM> and <NUM> diopter.