HK1060505A - Methods of obtaining ophtalmic lenses providing the eye with reduced aberrations - Google Patents

Description

Method for obtaining an ophthalmic lens capable of reducing ocular aberrations

Technical Field

The present invention relates to methods of designing and selecting ophthalmic lenses that reduce aberrations of the eye, and lenses that provide such vision improving effects.

Background of the invention

In addition to the first order defocus and astigmatism of the eye, a number of other visual defects may also be present, such as aberrations of different orders that occur when the wavefront passes through a refractive surface. The wavefront itself becomes aspherical when passing through a defective optical surface, whereas an aspherical wavefront creates a visual defect when it falls on the retina. Both of these types of visual defects can result if the cornea and the capsular bag lens are not defect-free or do not fully compensate for the optical elements. The term "asphericity" herein includes asphericity and asymmetry. The aspherical surface may be either a rotationally symmetric surface or a rotationally asymmetric surface and/or an irregular surface, i.e. all surfaces are not spherical.

The problem is being discussed that the vision of an eye with an implanted intraocular lens (IOL) is comparable to that of a normal eye of a person of the same age. Thus, a 70 year old cataract patient can only expect to obtain vision in the same age of the person without cataract after performing intraocular lens implantation surgery, although it is objectively believed that such a lens is optically superior to the natural crystalline lens. This conclusion can be explained by the fact that current IOLs are not adapted to compensate for age-related deficiencies of the optical system of the human eye. Age-related ocular defects have been studied and contrast sensitivity has been found to be significantly reduced in subjects older than 50 years of age. These conclusions seem to be consistent with the discussion above, since contrast sensitivity tests indicate that persons who have undergone cataract surgery with lens implants do not achieve better contrast sensitivity than persons with an average age of 60 to 70 years.

Although intraocular lenses have been developed with superior optical properties intended to replace defective cataractous lenses and other ophthalmic lenses such as conventional contact lenses or intraocular correction lenses, it is clear that they fail to correct a large number of ocular aberration phenomena, including age-related aberration defects.

Us patent 5,777,719(Williams et al) discloses a method and apparatus for accurately measuring higher order ocular aberrations using wavefront analysis using the human eye as an optical system. By using a Hartmann-Shack wavefront sensor, the higher order aberrations of the eye can be measured and corrected using the data obtained, and thus sufficient information to design an optical lens that provides highly improved optical correction. The Hartmann-Shack sensor provides a means for obtaining light reflected from the retina of the eye of a subject. The wavefront in the pupil plane is reconstructed at the plane of the lenslet array of the Hartmann-Shack sensor. Each lenslet in the lenslet array is used to form an aerial image of a retinal point source on a CCD camera at the focal plane of the array. In the form of a point source of light produced on the retina by the laser beam, the ocular wave aberration displaces each spot by an amount proportional to the local tilt of the wavefront on each lenslet. The output of the CCD camera is fed into a computer and then calculated to fit the slope data to the first derivative of 65 Zernike (Zernike) polynomials. By calculation, the coefficients of the weighted Zernike polynomials can be obtained. The weighted summation of Zernike polynomials represents the reconstructed wavefront that is distorted by the aberrations of the eye as an optical system. The terms of the Zernike polynomials represent aberrations in different modes.

Us patent 5,050,981(Roffman) discloses another method of designing a lens, which is achieved by: a number of rays passing through the lens-eye system are traced, and then the modulation transfer function is calculated from these rays and the density distribution of the rays at the imaging location is evaluated. This process is repeated by changing at least one lens surface until a lens is found that produces a sharp focus and minimal imaging aberrations.

The above-described method for designing is suitable for designing contact lenses or other corrective lenses for phakic eyes, which perfectly compensate for aberrations of the entire eye system. However, in order to provide a modified intraocular lens suitable for placement in the anterior chamber (anterior chamber) or posterior chamber (postero chamber) between the cornea and the capsular bag lens, the aberrations of the various parts of the eye need to be taken into account.

Recent efforts have been directed to the study of ocular aberrations, including a number of studies of the evolution of the aberrations as a function of age. In a particular study, the growth of individual parts of the eye was examined separately, and it was concluded that the Optical aberrations of individual parts of younger eyes cancel each other out, see Optical Letters, 1998, Vol.23 (21), 1713 and 1715. Also, S.Patel et al disclose the asphericity of the posterior surface of the cornea in a paper published 1993 by reflective & Corneal Surgery, Vol.9, p.173-181. The paper suggests that corneal data can be used with other ocular parameters to predict the optical performance and asphericity of an intraocular lens and thereby optimize the optical performance of future pseudophakic eyes. Furthermore, the shape of the cornea has recently been shown to change with age to become more spherical in shape by Antonio Guirao and PabloArtal, Vol.40 (4), published in 1999, S535. These studies show that the cornea of the subjects provides positive spherical aberration and increases with age. In visual research, vol.38 (2), page 209-229, 1998, A glass et al studied the spherical aberration of the natural lens after removal of the cornea obtained from the eye bank. According to the laser scanning optical method used here, it was found that the spherical aberration of the older lens (66 years old) showed uncorrected (positive) spherical aberration, while the lens 10 years old showed overcorrected (negative) spherical aberration.

In view of the foregoing, it is apparent that there is a need for an ophthalmic lens that is better suited for compensating for aberrations arising from various surfaces of the eye, such as the corneal surface and the surface of the lens in the capsular bag, and that is better able to correct aberrations other than defocus and astigmatism, as can be provided by conventional ophthalmic lenses.

Disclosure of Invention

It is an object of the present invention to improve the visual quality of the eye.

It is a further object of the present invention to provide a method for obtaining an ophthalmic lens that reduces aberrations of the eyeball.

Another object of the present invention is to provide a method for obtaining an intraocular lens capable of reducing the aberrations of the eye after implantation in the eye. It is a further object of the present invention to provide a method for obtaining an intraocular lens capable of compensating for aberrations due to optical irregularities of the corneal surface and the lens surface in the capsule.

It is a further object of the present invention to provide an intraocular lens which, together with a lens in the capsule, is capable of restoring a wavefront that deviates from spherical to a wavefront that substantially approximates spherical.

It is a further object of the present invention to provide an intraocular lens which can improve the visual quality of patients who have undergone corneal surgery or patients with corneal defects or diseases.

The present invention relates generally to a method for obtaining an ophthalmic lens that reduces aberrations of the eye. The aberration herein refers to wavefront aberration. It is based on the understanding that the converging wavefront must be perfectly spherical to form a point image, i.e. the wavefront passing through the optical surfaces of the eye, such as the cornea and the natural lens, must be perfectly spherical if a perfect image is to be formed on the retina of the eye. If the wavefront deviates from spherical, an aberrated image is formed, which is the case when the image passes through an imperfect lens system. The wavefront aberrations can be expressed in mathematical terms according to different approximate models, as explained in the reference book, for example as described in the 10 th edition optical, published by m.r. freeman in 1990.

In a first embodiment, the present invention relates to a method of designing an intraocular lens capable of reducing aberrations of an eye after intraocular implantation. The method includes a first step of measuring a wavefront aberration of an uncorrected eye using a wavefront sensor. And measuring the shape of at least one corneal surface in the eye using a corneal topographer. The at least one corneal surface and an intracapsular lens of an eye including the cornea are characterized with a mathematical model and the mathematical model is used to calculate the resulting aberrations of the corneal surface and the intracapsular lens. The capsular bag lens may be a natural lens or any kind of implanted lens. Hereinafter, the lens in the capsule is referred to as an intracapsular lens. From this is derived a representation of the aberrations of the cornea and the lens in the capsule, i.e. the wavefront aberrations of the wavefront passing through the corneal surface and the lens. The aberrations can be calculated in different ways depending on the mathematical model chosen. Preferably, the features of the corneal surface and the capsular bag lens are represented by a mathematical model of a rotating cone or a polynomial or a combination of both. More preferably, the features of the corneal surface and the capsular bag lens are expressed in a linear combination of polynomials. The second step of the method is the selection of the power of the intraocular correction lens, which is done according to conventional methods employed for the particular need of optical correction of the eye. Modeling an intraocular correction lens according to the information of steps one and two to obtain reduced aberrations in the wavefront of an optical system comprising said correction lens and mathematical models of the cornea and the capsular bag lens. In the creation of the lens model, the optical system considered generally comprises the cornea, the capsular bag lens and said correction lens, but in the specific case may also comprise other optical elements, as the case may be, an ophthalmic lens, or an artificial correction lens, such as a contact lens, or an implantable correction lens.

Modeling the lens includes selecting one or more lens parameters of the system that help determine the shape of the lens for a given diopter. This typically includes selecting the anterior radius and anterior surface shape, the posterior radius and posterior surface shape, the lens thickness, the lens index of refraction, and the position of the lens in the eye. In practice, the lens may be modeled based on data from a corrective lens as described in Swedish patent application Ser. No. SE-0000611-4, which is incorporated herein by reference. In this case, it is preferable to select a model that deviates as little as possible from the model that has been clinically determined. For this reason, it is preferable to keep predetermined values of the central radius, thickness and refractive index of the lens constant while selecting the front surface or the rear surface of different shape so that the surface of the lens is an aspherical surface or an asymmetrical shape. Another method of the present invention is to model the spherical front surface of a conventional starting lens by selecting the appropriate aspheric component. Aspheric design of lenses is a well-known technique and such design can be implemented according to different principles. The construction of such a surface is described in more detail in the swedish patent application 0000611-4 of the applicant, co-pending with the present application, and is incorporated herein by reference. As described above, the term "aspherical surface" is not limited to a symmetrical surface. For example, a radially asymmetric lens may be used to correct coma.

The method of the invention can be further developed by comparing the aberrations of the optical system including the mathematical models of the cornea and the capsular bag lens and the correction lens with the aberrations of the cornea and the capsular bag lens and assessing whether the aberrations are sufficiently reduced. From the above-mentioned physical parameters of the lens, suitable variable parameters are obtained, which can be varied to find a lens model which deviates sufficiently from a spherical lens to compensate for aberrations.

By using a wavefront sensor that measures the total aberration of the eye and directly measuring the corneal surface according to well-known topographical measurement methods, it is possible to characterize at least one corneal surface and the capsular bag lens as mathematical models and thus build up a mathematical model of the cornea and the capsular bag lens representing the aberrations, which helps to express the irregularities of the cornea with a quantifiable model that can be used in the present invention. From both measurements, the aberrations of the capsular bag lens can also be calculated and represented in aberration terms, such as a linear combination of polynomials representing the aberrations of the capsular bag lens. The aberrations of the capsular bag lens can be obtained by using the wavefront aberration values of the entire eye and subtracting the wavefront aberration values of the cornea from these values, or alternatively by modeling the optical system in such a way that, starting from a model of the cornea measured on the cornea and of the capsular bag lens of the "starting point", the aberrations of the system are calculated and then the capsular bag lens is subjected toUntil the calculated aberration is sufficiently similar to the measured aberration of the uncorrected eye. Corneal measurements for this purpose can be made by Orbtek, L.L.C., Inc. ORBSCAN^Corneal telekeratometry (videokeratograph), or by corneal topography, such as, but not limited to, EyeSys^Or Humphrey Atlas^And then realized. Preferably, at least the anterior surface of the cornea, and more preferably both the anterior and posterior surfaces of the cornea, are measured and characterized and expressed in aberration terms, such as a linear combination of polynomials representing the total corneal aberration. According to an important aspect of the invention, characterization of the cornea and the capsular bag lens is performed in a selected population to represent an average of aberrations and to design a lens based on the average aberrations. The average aberration term for a population can then be calculated, for example as the average linear combination of polynomials, and used in the lens design method. This aspect involves selecting different relevant populations, for example, grouped by age, to produce an appropriate average corneal surface and capsular bag lens that will conform to each design approach. In this way, the patient will obtain a lens with less aberrations compared to a conventional lens which is substantially spherical.

Preferably, the above mentioned measuring also comprises measuring the refractive power of the eye. In the design method of the present invention, in order to select the diopter of the lens, the diopter of the cornea and the capsular bag lens and the axial length of the eyeball are generally considered.

Also preferably, here the wavefront aberrations are expressed as a linear combination of polynomials and the optical system comprising the mathematical models of the cornea and the capsular bag lens and the modeled intraocular correction lens provides a significantly reduced wavefront with aberrations as expressed by the terms of one or more of such polynomials which terms can be used by the skilled person in the optical arts to describe aberrations. The polynomial is preferably Seidel or Zernike polynomial. Zernike polynomials are preferred according to the present invention.

The use of Zernike terms to describe wavefront aberrations arising from deviations from aberration-free optical surfaces is a state-of-the-art technique and can be used, for example, withHartmann-Shack sensors are used together, as outlined in J.Opt.Soc.am., 11(7), vol. 1949-57, published 1994. It is widely accepted in the optical profession that different Zernike terms represent different aberration phenomena, including defocus, astigmatism, coma, spherical aberration and higher order forms of aberration. In one embodiment of the method, the measurement of the corneal surface and the capsular bag lens results in the corneal surface shape and the capsular bag lens shape being expressed as a linear combination of Zernike polynomials (as shown in equation (1)), where Zi is the ith Zernike term, a_iIs the weighting coefficient of the term. Zernike polynomials are a set of perfectly orthogonal polynomials defined on a unit circle. Table 1 below shows the first 15 zernike terms, and the aberrations represented by each term, which can be of the fourth order.

In equation (1), ρ and θ represent the normalized radius and the azimuth angle, respectively.

TABLE 1

Conventional optical correction using an intraocular lens satisfies only the fourth term of an optical system of an eyeball including an implanted lens. The fifth and sixth terms can be further satisfied by spectacles, contact lenses and intraocular lenses that can correct astigmatism, thereby significantly reducing Zernike polynomials that relate to astigmatism.

The method of the present invention further includes calculating aberrations produced by an optical system comprising the modeled intraocular correction lens and the mathematical models of the cornea and the capsular bag lens in a linear combination of polynomials and determining whether the intraocular correction lens substantially reduces the aberrations. If the aberration is not sufficiently reduced, the lens will be re-modeled until one or more terms of the polynomial are sufficiently reduced. Re-modeling the lens means changing at least one conventional lens design parameter. These parameters include the anterior surface shape and/or central radius, the posterior surface shape and/or central radius, the lens thickness and its refractive index. Typically, such re-modeling involves changing the curvature of the lens surface so that it deviates from an exact spherical surface. There are several tools available for lens design that can be used in this design method, such as OSLO 5 th edition, see Sinclair Optics, chapter 4, programReference, 1996.

According to a preferred aspect of the first embodiment, the method of the present invention comprises expressing at least one corneal surface and the shape of the capsular bag lens as a linear combination of Zernike polynomials and thereby determining the Zernike coefficients of the wavefront of the cornea and the capsular bag lens, i.e. the coefficients of each of the selected Zernike polynomials. The corrective lens is then modeled such that an optical system including the modeled corrective lens and mathematical models of the cornea and the capsular bag lens provides a wavefront having substantially reduced selected Zernike coefficients. The process can be further improved by the following steps: calculating Zernike coefficients representing Zernike polynomials of a wavefront produced by an optical system comprising the modeled intraocular correction lens and mathematical models of the cornea and the capsular bag lens, determining whether the lens provides substantially reduced Zernike coefficients for the wavefront of the cornea and the capsular bag lens; and the lens may be re-modeled until the coefficients are sufficiently reduced. This aspect of the method preferably takes into account that the Zernike polynomials can reach the fourth order and the aim is to substantially reduce the Zernike coefficients related to spherical aberration and/or astigmatism terms. It is desirable to sufficiently reduce the 11 th Zernike coefficient of the wavefront produced by an optical system comprising mathematical models of the cornea and the capsular bag lens and the modeled intraocular correction lens, so that an eyeball with substantially eliminated spherical aberration can be obtained. Another aspect of the present design method may include reducing higher order aberrations, whereby the method aims to reduce the zernike coefficients of the aberration terms of higher order than the fourth order.

When designing lenses based on the topography of the cornea and capsular bag lens of a selected population, the corneal surface and capsular bag lens of each individual are preferably represented in Zernike polynomials, from which the Zernike coefficients are determined. From these results, the average Zernike coefficients are calculated and applied to the design method to substantially reduce the selected coefficients. It is noted that the final lens obtained by the design method based on the average of a large group of people has the objective of significantly improving the visual quality for all users. As a result, a lens that completely eliminates the aberration term based on the average value may not be suitable for a particular individual, resulting in poorer vision than wearing a conventional ophthalmic lens. For this reason, the selected Zernike coefficients may be appropriately reduced from the average value by a certain degree or a predetermined ratio.

According to another aspect of the inventive design method, the characterization of the cornea and capsular bag lens of a selected population and the resulting linear combination of polynomials, such as Zernike polynomials, generated for each person's corneal and capsular bag lens aberrations can be compared in terms of coefficient values. Based on this result, appropriate coefficient values are selected for the appropriate lens and used in the inventive design method. Such a coefficient value may typically be the lowest value in a selected population of people with aberrations of the same sign, and therefore a lens designed according to this value may provide improved visual quality for all people in the group compared to conventional lenses.

According to another embodiment, the present invention is directed to selecting an intraocular lens having refractive power suitable for optical correction of a patient from a plurality of lenses having the same refractive power but different aberrations. This selection method is similarly carried out according to the design method described in the method of the invention and comprises the characterization of at least one corneal surface and the capsular bag lens by means of a mathematical model and the calculation of the aberrations of the corneal surface and the capsular bag lens therefrom. The optical system comprising the selected correction lens and the mathematical models of the cornea and the capsular bag lens is then evaluated to take into account whether the wavefront aberration resulting from calculating such a system achieves a sufficient reduction of the aberration. If insufficient correction is found, another lens with the same power but different aberrations is selected. The mathematical models used here are similar to those described above and the same characterization methods for the corneal surface and the capsular bag lens can be used.

Preferably, this selectively determined aberration is expressed as a linear combination of Zernike polynomials and the resulting Zernike coefficients of the optical system including the mathematical models of the cornea and the capsular bag lens and the selected correction lens are calculated. From the coefficient values of the system, it can be determined whether the intraocular correction lens adequately balances the corneal and capsular bag lens aberration terms, as described by the Zernike coefficients of the optical system. If the expected individual coefficients are found not to be sufficiently reduced, these steps are repeated by selecting another correction lens having the same power and different aberrations until a lens is found that is effective in reducing the aberrations of the optical system. Preferably, at least 15 Zernike polynomials are determined, up to order 4. If it is considered that the spherical aberration is effectively corrected, only the spherical aberration term of Zernike polynomials of the optical system including the cornea and the capsular bag lens and the intraocular correction lens is corrected. It is noted that the intraocular correction lens should be selected such that the choice of those items for the optical system comprising the correction lens and the cornea and the capsular bag lens becomes sufficiently small. According to the present invention, the eleventh Zernike coefficient, a, can be substantially eliminated₁₁Or to be sufficiently close to 0. This is a prerequisite for obtaining an intraocular correction lens that sufficiently reduces spherical aberration of the eyeball. By considering other Zernike coefficients in the same way, the method of the invention can be used to correct other types of aberrations than spherical aberration, such as those representing astigmatism, coma and higher order aberrations. Higher order aberrations can also be corrected depending on the number of Zernike polynomials selected as part of the model, in which case a correction lens can be selected that can correct higher order aberrations than the fourth order.

According to an important aspect, the selection method includes selecting a corrective lens from a set of corrective lenses having a range of powers, and a plurality of corrective lenses of each power having different aberrations. In one embodiment, the plurality of corrective lenses of each diopter have anterior surfaces with different aspheric components. If the first correcting lens does not exhibit sufficient reduction in aberrations, as expressed in the appropriate Zernike coefficients, then another correcting lens having the same power but a different surface is selected. This selection method can be repeated, if desired, until an optimally corrected lens is found or the aberration term under study falls below the effective boundary value. In fact, the Zernike terms obtained by corneal and capsular bag lens examination will be directly available to the ophthalmologist and by means of an algorithm they will be compared with the known Zernike terms of the set of corrective lenses. The most suitable corrective lens in the set can be found by comparison and implanted.

The invention further relates to an intraocular correction lens having at least one aspherical surface, which is capable of converting a wavefront passing through the cornea of the eye into a wavefront which, after passing through the correction lens, passes through the capsular bag lens and is converted into a wavefront which is substantially spherical and centered on the retina of the eye. Preferably, the wavefront is substantially spherical corresponding to the aberration term representing when the aberration term of the rotationally symmetric Zernike term reaches the fourth order.

In accordance with a particularly preferred embodiment of the present invention, the present invention is directed to an intraocular correction lens having a fourth order 11 th term (i.e., the Zernike coefficients a) when the aberration is calculated and expressed as a linear combination of Zernike polynomial terms₁₁) Spherical aberration of the wavefront passing through the eyeball can be substantially reduced after implantation of the corrective lens. In one aspect of this embodiment, the Zernike coefficients a of the corrective lens are determined₁₁To compensate for the corneal and capsular bag Zernike coefficients a of sufficient magnitude₁₁The average of the estimates. In another aspect, Zernike coefficients a are determined₁₁To compensate forCoefficients of the cornea and the capsular bag lens of individual patients. Thus, a lens with high accuracy can be customized for an individual.

The lens according to the invention can be produced in a conventional manner. In one embodiment, they are made of a soft, resilient material, such as silicone or hydrogel. Examples of such materials are described in WO 98/17205. The manufacture of aspherical silicone lenses or similarly foldable lenses can be achieved according to us patent 6,007,747. The lens according to the invention may also be made of a more rigid material, such as polymethyl (meth) acrylate. Those skilled in the art can readily determine alternative materials and manufacturing methods to produce the aberration-reducing lenses of the invention.

In a preferred embodiment of the invention, the intraocular correction lens is adapted for implantation in the posterior chamber of the eye between the iris and the capsular bag lens. The corrective lens according to this embodiment preferably comprises a centrally located optical portion capable of providing an optical correction, and a peripherally located support element capable of holding the optical portion in the central position, the optical portion and the support element each having a concave posterior surface constituting part of an aspheric surface. The intersection between the aspheric surface and any one of the planes containing the optical axis represents a perfect curve without discontinuities and deformed points. Such an intraocular correction lens without the reduced aberrations of the present invention is described in SE-0000611-4. This lens design is preferred as it adapts to the anatomy of the eyeball and avoids stress on the lens. Due to this design, contact between the natural lens and the iris can be avoided or minimized.

The method of designing such a preferred corrective lens preferably comprises the steps of:

-evaluating the anterior radius of the capsular lens in the non-accommodated state;

-selecting a corrective lens posterior central radius that is different from the posterior central radius of the capsular bag lens in the non-accommodated state;

-determining the total corrective lens vault from the data obtained in steps (i) and (ii);

-selecting a perfect curve without deformed points, the curve representing the intersection of the posterior surface and a plane comprising the optical axis, thereby providing an aspherical posterior surface of the corrective lens surface.

In another embodiment of the invention, the corrective lens is adapted to be placed in the anterior chamber of the eye and secured to the iris. This embodiment has the advantage that the correction lens is attached to the iris, cannot be moved around, and cannot be rotated, thus making it more suitable for correcting asymmetric aberrations.

The invention also relates to a method of improving the vision of an eye. The intraocular correction lens described above is implanted into an eye according to the present invention. Vision can also be further improved by wearing glasses or corrective glasses outside the eye or by adjusting the cornea using, for example, a laser.

The ophthalmic lens according to the invention is particularly suitable for being designed and manufactured for correcting aberrations induced by corneal surgery, such as LASIC (laser keratomileusis) and PRK (radial keratotomy). The cornea and the entire eyeball of the patient who has undergone the corneal surgery are measured as described above, and the correction lens is designed based on these measured values. The lens according to the invention is also suitable for being designed for patients with corneal defects or corneal diseases.

The lenses described according to the invention can be designed either individually for each individual or for a group of individuals.

The invention also relates to a method for improving the visual quality of an eye, wherein a corneal surgery is first performed on the eye. Wavefront analysis of the eye is then performed after the cornea is restored. If the aberrations of the eye have to be reduced, a corrective lens suitable for this person is designed according to the above description. This corrective lens is then implanted into the eye. Different types of corneal surgery are possible. Two common methods are LASIK and PRK, as described in J Rowsey et al, 1998, published under the Survey of Ophthalmology, Vol.43 (2), p.147-156. The method of the invention has the particular advantage that a person who has undergone corneal surgery and has significant visual defects can obtain perfect visual quality. This is difficult to achieve with conventional surgery.

Claims (82)

1. A method of designing an intraocular correction lens capable of reducing aberrations of an eye after implantation thereof in an eye and adapted to be placed between a cornea and a lens capsule of the eye, comprising the steps of:

(i) measuring a wavefront aberration of the uncorrected eye with a wavefront sensor;

(ii) measuring the shape of at least one corneal surface in the eye with a corneal topographer;

(iii) characterizing the at least one corneal surface and a lens of the lens in a capsule of an eye comprising said cornea as a digital model;

(iv) calculating a final aberration of the corneal surface and the capsular bag lens using the mathematical model;

(v) selecting an optical power of the intraocular correction lens;

(vi) an intraocular correction lens model is established such that a wavefront produced by an optical system comprising the intraocular correction lens and mathematical models of the cornea and the capsular bag lens obtains reduced aberrations.

2. The method of claim 1, wherein the corneal surface and the intracapsular lens are characterized by a rotating cone.

3. The method of claim 1, wherein said corneal surface and said intracapsular lens are characterized by a polynomial.

4. The method according to claim 3, wherein said corneal surface and said intracapsular lens are characterized by a linear combination of polynomials.

5. The method of claim 1, wherein characterizing the capsular bag lens as a mathematical model is accomplished by subtracting a measurement of the wavefront aberration of the cornea from a measurement of the wavefront aberration of the entire eye.

6. The method of claim 5, wherein the wavefront aberration is measured across the eye using a wavefront sensor and the corneal shape is measured using topography.

7. The method of claim 1, wherein the optical system further comprises a supplemental device for optical correction, such as an ophthalmic lens or an ophthalmic correction lens.

8. The method according to claim 1, wherein the evaluation of the corneal and capsular bag lens refractive power and the axial eye length determines the selection of the corrective lens optical power.

9. A method according to claim 3, wherein the optical system comprising the model of the cornea and the capsular bag lens and the optical system of the modeled intraocular correction lens provides a wavefront substantially reduced in aberrations represented by at least one of said polynomials.

10. The method of claim 1, wherein modeling the intraocular correction lens comprises selecting an anterior radius and anterior surface shape, a posterior radius and posterior surface shape, a thickness, and a refractive index of the lens.

11. The method of claim 10, wherein the aspheric component of the anterior surface of the model lens having the predetermined central radius, thickness and refractive index is selected.

12. The method of claim 1, wherein the intraocular correction lens is adapted for implantation in the posterior chamber of the eye between the iris and the lens capsule, the method further comprising the steps of:

(i) evaluating an anterior radius of the capsular bag lens in an unaccommodated state;

(ii) selecting a posterior central radius of the corrective lens that is different from a posterior central radius of the capsular bag lens in the non-accommodated state;

(iii) (iii) determining the total corrective lens vault from the data obtained in steps (i) and (ii);

(iv) a perfect curve representing the intersection of the posterior surface with a plane containing the optical axis without the deformed point is selected to provide the non-spherical posterior surface of the corrective lens.

13. The method of claim 1, wherein the intraocular correction lens is adapted for implantation into the anterior chamber of the eye and/or fixation to the iris.

14. A method according to claim 1, comprising characterizing the anterior corneal surface of the individual by means of topographical measurements and expressing the corneal aberrations as a combination of polynomials.

15. A method according to claim 14, comprising characterizing the anterior and posterior surfaces of the cornea of the individual by means of topographical measurements, and expressing the total corneal aberration as a combination of polynomials.

16. The method of claim 1, comprising characterizing the corneal surface and the natural lens of a selected population and expressing the average aberrations of the cornea and the natural lens in said population as a combination of polynomials.

17. The method of claim 1, further comprising the steps of:

(v) calculating an aberration of a wavefront produced by the optical system;

(vi) determining whether the modeled intraocular correction lens sufficiently reduces aberrations of a wavefront produced by the optical system, and optionally reconstructing the intraocular correction lens model until sufficiently reduced aberrations are obtained.

18. The method of claim 17, wherein the aberration is represented by a linear combination of polynomials.

19. The method of claim 18, wherein reconstructing the model includes altering one or more of the anterior surface and curvature, posterior radius and surface, lens thickness, and refractive index of the corrective lens.

20. A method according to claim 3 or 4, wherein the polynomial is a Seidel or Zernike polynomial.

21. The method of claim 20, comprising the steps of:

(i) expressing the aberrations of the cornea and the capsular bag lens by a linear combination of Zernike polynomials;

(ii) determining Zernike coefficients describing the shape of the cornea and the capsular bag lens;

(iii) an intraocular correction lens model is established such that a wavefront passing through an optical system comprising the modeled correction lens and Zernike polynomial models of the capsular bag lens and cornea obtains substantially reduced Zernike coefficients of the system's final wavefront aberrations.

22. The method of claim 21, further comprising the steps of:

(iv) calculating Zernike coefficients of a wavefront generated by the optical system;

(v) determining whether the intraocular correction lens provides sufficiently reduced Zernike coefficients, and optionally reconstructing the lens model until a sufficient reduction of the coefficients is obtained.

23. A method according to claim 22, comprising substantially reducing zernike coefficients related to spherical aberration.

24. A method according to claim 22, comprising substantially reducing zernike coefficients related to aberrations beyond the fourth order.

25. A method according to claim 23, comprising substantially reducing the eleventh zernike coefficient of the wavefront of the optical system, thereby obtaining an eye substantially free of spherical aberration.

26. The method of claim 22, wherein reconstructing the model includes altering one or more of the anterior radius and surface shape, the posterior radius and surface shape, the thickness, and the refractive index of the corrective lens.

27. The method of claim 26, comprising changing the shape of the anterior surface of the corrective lens until a sufficient reduction in aberrations is obtained.

28. The method of claim 20, comprising modeling the intraocular correction lens such that the optical system provides reduced spherical and cylindrical aberration terms of a wavefront passing through the system as represented by seidel or zernike polynomials.

29. A method according to claim 28, obtaining a reduction of higher order aberration terms.

30. The method of claim 9, comprising:

(i) characterizing the corneal surface and the capsular bag lens of the selected population and expressing each cornea and each capsular bag lens in a linear combination of polynomials;

(ii) comparing polynomial coefficients between different combinations of the cornea and the capsular bag lens of each individual;

(iii) selecting a nominal coefficient value based on the cornea and the capsular bag lens of an individual;

(iv) a corrective lens model is established such that the wavefront produced by the polynomial model optical system including the corrective lens and the capsular bag lens and cornea substantially reduces the nominal coefficient values.

31. A method according to claim 30, wherein said polynomial coefficients relate to zernike aberration terms representing spherical aberration.

32. A method according to claim 30, wherein said nominal coefficient value is the lowest value in the selected population.

33. A method of selecting an intraocular correction lens capable of reducing aberrations of an eye after implantation thereof, the method comprising the steps of:

(i) characterizing at least one corneal surface and a lens in a capsule of an eye comprising the cornea as a mathematical model;

(ii) calculating a final aberration of the corneal surface and the capsular bag lens using the mathematical model;

(iii) selecting an intraocular correction lens having an appropriate optical power from a plurality of lenses having the same optical power but different aberrations;

(iv) determining whether an optical system comprising the selected corrective lens and the mathematical models of the capsular bag lens and cornea substantially reduces aberrations.

34. The method of claim 33, further comprising the steps of:

(v) calculating a wavefront aberration generated by the optical system;

(vi) determining whether the selected intraocular correction lens substantially reduces wavefront aberrations produced by the optical system; and optionally repeating steps (iii) and (iv) by selecting at least one further corrective lens having the same optical power until a corrective lens is found that is capable of substantially reducing aberrations.

35. The method of claim 33, wherein the corneal surface and the intracapsular lens are characterized by a rotating cone.

36. The method of claim 33, wherein said corneal surface and said intracapsular lens are characterized by a polynomial.

37. The method of claim 36, wherein the corneal surface and the intracapsular lens are characterized by a linear combination of polynomials.

38. A method according to claim 33, wherein the total aberration of the eye and the aberration of the cornea are measured, these measurements giving the respective aberrations of the cornea and the capsular bag lens.

39. The method of claim 38, wherein the total aberration of the eye is measured using a wavefront sensor and the aberration of the cornea is measured using a topography.

40. A method according to claim 33 or 34, wherein the optical system further comprises supplementary means for optical correction, such as an ophthalmic lens or an ophthalmic correction lens.

41. The method according to claim 33, wherein the evaluation of the corneal and capsular bag lens refractive power and the axial eye length determines the selection of the corrective lens optical power.

42. A method according to claim 36 or 37, wherein a model comprising said cornea and capsular bag lens and the selected intraocular correction lens optical system provides said aberration substantially reduced wavefront by aberration represented by at least one of said polynomials.

43. The method of claim 33, wherein the intraocular correction lens is adapted for implantation in the posterior chamber of the eye between the iris and the lens capsule, the method further comprising the steps of:

(i) evaluating an anterior radius of the capsular bag lens in an unaccommodated state;

(ii) selecting a posterior central radius of the corrective lens that is different from a posterior central radius of the capsular bag lens in the non-accommodated state;

(iii) (iii) determining the total corrective lens vault from the data obtained in steps (i) and (ii);

(iv) a perfect curve representing the intersection of the posterior surface and a plane containing the optical axis without the deformed point is selected to provide the non-spherical posterior surface of the corrective lens.

44. The method of claim 33, wherein the intraocular correction lens is adapted for implantation in the anterior chamber of the eye and fixation to the iris.

45. A method according to claim 33, comprising characterizing the anterior corneal surface of an individual by means of topographical measurements and expressing the corneal aberrations as a combination of polynomials.

46. A method according to claim 45, comprising characterizing the anterior and posterior corneal surfaces of an individual by means of topographical measurements, and expressing the total corneal aberration as a combination of polynomials.

47. A method according to claim 33, comprising characterizing corneal surfaces and the capsular bag lens of a selected population by means of topographical measurements, and expressing average aberrations of the cornea and the capsular bag lens in said population as a combination of polynomials.

48. A method according to claim 42, wherein the polynomial is a Sdidel or Zernike polynomial.

49. The method of claim 48, comprising the steps of:

(i) determining wavefront aberrations of the cornea and the capsular bag lens;

(ii) expressing the aberrations of the cornea and the capsular bag lens by a linear combination of Zernike polynomials;

(iii) the intraocular correction lens is selected such that a wavefront passing through an optical system comprising said correction lens and Zernike polynomial models of the cornea and the capsular bag lens achieves a sufficient reduction of the Zernike coefficients.

50. The method of claim 49, further comprising the steps of:

(iv) calculating Zernike coefficients of a wavefront generated by the optical system;

(v) determining whether said intraocular correction lens provides a sufficient reduction in Zernike coefficients and arbitrarily selecting another lens until a sufficient reduction in said coefficients is obtained.

51. A method according to claim 49 or 50, comprising determining Zernike polynomials of up to a fourth order.

52. A method according to claim 51, comprising substantially reducing Zernike coefficients related to spherical aberration.

53. A method according to claim 52, comprising substantially reducing Zernike coefficients beyond the fourth order aberration.

54. A method according to claim 52, comprising substantially reducing the eleventh Zernike coefficient of the wavefront generated by the optical system, thereby obtaining an eye substantially free of spherical aberration.

55. The method of claim 45, comprising selecting the intraocular correction lens such that the optical system provides a reduced spherical aberration term in Seidel or Zernike polynomials to a wavefront passing through the system.

56. The method of claim 45, wherein a reduction of higher order aberration terms is achieved.

57. The method of claim 33, wherein the intraocular correction lens is selected from a group of lenses comprising lenses having suitable optical power ranges, and wherein a plurality of the lenses in each optical power range have different aberrations.

58. The method of claim 57, wherein said aberration is spherical aberration.

59. The method of claim 57, wherein said corrective lenses in each optical power range have surfaces with different aspheric components.

60. The method of claim 59, wherein the surface is an anterior surface.

61. An intraocular correction lens obtained according to any one of claims 1 to 60, which in combination with the capsular bag lens of the eye is capable of transforming a wavefront passing through the cornea of the eye into a substantially spherical wavefront centred on the retina of the eye.

62. An intraocular correction lens according to claim 61, capable of compensating aberrations of models of the cornea and the capsular bag lens designed according to the appropriate population, so that a wavefront produced by an optical system comprising said correction lens and said models of the cornea and the capsular bag lens obtains significantly reduced aberrations.

63. An intraocular correction lens according to claim 62, wherein said models of the cornea and the capsular bag lens include an average aberration term calculated by characterizing the individual cornea and the capsular bag lens and representing them in mathematical terms to yield a single aberration term.

64. An intraocular correction lens according to claim 63, wherein said aberration terms are linear combinations of Zernike polynomials.

65. An intraocular correction lens according to claim 64, capable of reducing aberration terms expressed in Zernike polynomials of said models of the cornea and the capsular bag lens, such that a wavefront produced by an optical system comprising said correction lens and said models of the cornea and the capsular bag lens results in a significantly reduced spherical aberration.

66. An intraocular correction lens according to claim 65, which is capable of reducing the eleventh Zernike term of the fourth order aberrations.

67. An intraocular correction lens having at least one aspherical surface which, when its aberrations are expressed as a linear combination of polynomial terms, in combination with the capsular bag lens of the eye, is capable of reducing such aberration terms similarly obtained for a wavefront passing through the cornea, thereby obtaining an eyeball substantially free of aberrations.

68. The intraocular correction lens of claim 67, wherein the aspheric surface is an anterior surface of the lens.

69. The intraocular correction lens of claim 67, wherein the aspheric surface is a posterior surface of the lens.

70. An intraocular correction lens according to claim 69, wherein said polynomial term is a Zernike polynomial.

71. The intraocular correction lens of claim 70, which is capable of reducing polynomial terms representative of spherical aberration and astigmatism.

72. An intraocular correction lens according to claim 71, which is capable of reducing the eleventh zernike polynomial term of the fourth order aberrations.

73. An intraocular correction lens according to claim 72, made of a biocompatible soft material.

74. The intraocular correction lens of claim 73, made of silicone.

75. The intraocular correction lens according to claim 73, made from a hydrogel.

76. An intraocular correction lens according to claim 72, made of a biocompatible hard material.

77. An intraocular correction lens according to claim 67, adapted for implantation in the posterior chamber of an eye between the iris and the lens capsule, said intraocular correction lens comprising a centrally located optical portion capable of providing optical correction, and a peripherally located support element capable of holding said optical portion in said central position, said optical portion and said support element each having a concave posterior surface forming part of an aspheric surface, the intersection between said aspheric surface and any plane containing the optical axis representing a perfect curve without discontinuities and inflection points.

78. An intraocular correction lens according to claim 77, adapted for implantation in the anterior chamber of the eye and fixation on the iris.

79. A method of improving the visual quality of the eye, characterized by implanting an intraocular correction lens according to claims 67 to 78.

80. The method of claim 79 wherein an ophthalmic lens or ophthalmic corrective lens is worn outside the eye to further improve visual quality.

81. The method of claim 79, wherein the cornea of the patient receiving the intraocular correction lens has been modified by means of a laser.

82. A method of improving the visual quality of an eye, characterized by the steps of: -performing corneal surgery on the eye; -restoring the cornea; -performing a wavefront analysis of the eye; -designing a corrective lens according to any one of claims 1 to 15, 17 to 29, 33 to 46 and 48 to 60; and-implanting a corrective lens in the eye.