Ophthalmic lenses capable of reducing chromatic aberration

• US 7,677,725 B2
• Filed: 04/05/2005
• Issued: 03/16/2010
• Est. Priority Date: 04/05/2004
• Status: Active Grant

• Current Assignee: Amo Groningen
• Original Assignee: Amo Groningen B.V (Johnson & Johnson)
• Inventors: Piers, Patricia, Weeber, Henk
• Primary Examiner(s): Stultz; Jessica T
• Application Number:
  US11/099,342
• Publication Number:
  US 20070002444A1
• Time in Patent Office: 1,806 Days
• Field of Search: 351/177
• US Class Current: 351/177
• CPC Class Codes: A61F 2/1613 having special lens configurations, e.g. multipart lenses; having particular optical properties, e.g. pseudo-accommodative lenses, lenses having aberration corrections, diffractive lenses, lenses for variably absorbing electromagnetic radiation, lenses having variable focus
• CPC Class Codes: A61F 2/1637 Correcting aberrations caused by inhomogeneities; correcting intrinsic aberrations, e.g. of the cornea, of the surface of the natural lens, aspheric, cylindrical, toric lenses
• CPC Class Codes: A61F 2/1654 Diffractive lenses
• CPC Class Codes: A61F 2/1659 having variable absorption coefficient for electromagnetic radiation, e.g. photochromic lenses
• CPC Class Codes: A61F 2240/002 Designing or making customized prostheses
• CPC Class Codes: G02B 27/0012 Optical design, e.g. procedures, algorithms, optimisation routines
• CPC Class Codes: G02B 27/0037 with diffracting elements G02B27/0056 takes precedence; holographic optical elements G02B5/32; zone systems G02B5/1876
• CPC Class Codes: G02B 27/4211 correcting chromatic aberrations G02B27/0056, G02B27/4222, G02B27/4227 take precedence
• CPC Class Codes: G02B 3/04 with continuous faces that are rotationally symmetrical but deviate from a true sphere , e.g. so called "aspheric" lenses
• CPC Class Codes: G02B 5/1814 structurally combined with one or more further optical elements, e.g. lenses, mirrors, prisms or other diffraction gratings G02B5/189 takes precedence
• CPC Class Codes: G02C 2202/20 Diffractive and Fresnel lenses or lens portions
• CPC Class Codes: G02C 2202/22 Correction of higher order and chromatic aberrations, wave front measurement and calculation
• CPC Class Codes: G02C 7/02 Lenses; Lens systems ; Methods of designing lenses
• CPC Class Codes: G02C 7/027 considering wearer's parameters
• CPC Class Codes: G02C 7/028 Special mathematical design techniques

Abstract

A method of designing an aspheric ophthalmic lens with both refractive and diffractive powers that is capable of reducing chromatic aberration and at least one monochromatic aberration of an eye comprises combining aspherical refractive and diffractive surfaces, selecting an appropriate eye model, establishing a design lens having at least one aspheric surface with a capacity to reduce monochromatic aberration in said eye model, establishing a diffractive lens element that corrects for chromatic aberration of the model eye; and adjusting the lens surface design in order to obtain a suitably high polychromatic image quality in a form that is weighted to comply with a spectral merit function.

Claims

1. A method of designing an aspheric ophthalmic lens with both refractive and diffractive powers that is capable of reducing chromatic aberration and at least one monochromatic aberration of an eye characterized by combining aspherical refractive and diffractive surfaces, selecting an appropriate eye model, establishing a design lens having at least one aspheric surface with a capacity to reduce monochromatic aberration in said eye model, establishing a diffractive lens element that corrects for chromatic aberration of the model eye;

and adjusting the lens surface design in order to obtain a suitably high polychromatic image quality in a form that is weighted to comply with a spectral merit function, wherein said spectral merit function describes a wavelength dependent sensitivity of an eye for selected lighting conditions, wherein the spectral merit function is obtained from a combination of functions and wherein the functions are selected from the group consisting of photopic, scotopic, and mesotopic luminosity functions.

2. The method according to claim 1 including selecting a design wavelength deviating from the maximum sensitivity wavelength of the spectral merit function so the higher order foci generated from the diffractive lens element have sufficiently low efficiencies within the range of visible light.

3. The method according to claim 2, wherein the design wavelength is between 470 and 545 nm.

4. The method according claim 3, wherein the design wavelength is 500 nm.

5. The method according to claim 2, wherein the maximum sensitivity wavelength of the spectral merit function is 550 nm.

6. The method according to claim 1, wherein the design lens is provided with a wavelength filter that eliminates a wavelength range, or reduces transmission at selected wavelengths.

7. The method according claim 6, wherein the filter is a blue light chromophore.

8. The method according to claim 6, wherein the filter is equivalent to the natural crystalline lens at a specific age.

9. A method according to claim 1, wherein the lens is a monofocal lens.

10. The method of claim 1, wherein the design lens has an aspheric surface made to compensate for spherical aberration from a model cornea, wherein said model cornea is an average cornea resulting from averaged corneal topography determinations of an elected population, and wherein said population is elected to undergo cataract surgery.

11. The method according to claim 1, including evaluating if aberration terms signifying the aberrations of a wavefront have passing said design lens with a sufficiently chromatic aberration reducing diffractive element deviates from the preset capacity of the lens to correct for monochromatic aberration terms and optionally redesigning at least one surface of the design lens until the aberration terms sufficiently complies with said preset capacity.

12. The method according to claim 11, including evaluating aberration terms signifying spherical aberrations.

13. The method according to claim 11, wherein the surface redesign involves a change of the aspheric curve representing the lens surface.

14. The method according to claim 1, wherein said design lens is an intraocular lens.

15. A method of designing an aspheric ophthalmic lens with both refractive and diffractive powers that is capable of reducing chromatic aberration and at least one monochromatic aberration of an eye characterized by combining aspherical refractive and diffractive surfaces, selecting an appropriate eye model, establishing a design lens having at least one aspheric surface with a capacity to reduce monochromatic aberration in said eye model, establishing a diffractive lens element that corrects for chromatic aberration of the model eye;

adjusting the lens surface design in order to obtain a suitably high polychromatic image quality in a form that is weighted to comply with a spectral merit function, wherein said spectral merit function describes a wavelength dependent sensitivity of an eye for selected lighting conditions, wherein the spectral merit function is obtained from a combination of functions, and wherein the function is selected from the group consisting of photopic, scotopic, and mesotopic luminosity functions;

determining the efficiency for the higher order foci generated from the diffractive lens element, and introducing in said design lens a spectral filter that eliminates wavelengths or reduces transmission of wavelengths in a manner that said higher foci have reduced efficiency within the range of visible light.

16. The method according to claim 15, wherein the higher order focus is the second order focus and the spectral filter is a blue light filter.

17. The according to claim 16, wherein the blue light filter eliminates wavelengths below 420 nm.

18. A method of designing an aspheric ophthalmic lens with both refractive and diffractive powers that is capable of reducing chromatic aberration and at least one monochromatic aberration of an eve characterized by combining aspherical refractive and diffractive surfaces, selecting an appropriate eye model, establishing a design lens having at least one aspheric surface with a capacity to reduce monochromatic aberration in said eye model, establishing a diffractive lens element that corrects for chromatic aberration of the model eye;

and adjusting the lens surface design in order to obtain a suitably high polychromatic image quality in a form that is weighted to comply with a spectral merit function, wherein said spectral merit function describes a wavelength dependent sensitivity of an eye for selected lighting conditions, wherein the diffractive lens element is a diffractive surface profile consisting of a number of concentric rings, and wherein the profile height of the diffractive surface profile, when multiplied with a difference in refractive index between the design lens and a surrounding medium equals an integer number of the design wavelength.