LENS SURFACE WITH COMBINED DIFFRACTIVE, TORIC, AND ASPHERIC COMPONENTS

• US 20090164008A1
• Filed: 12/21/2007
• Published: 06/25/2009
• Est. Priority Date: 12/21/2007
• Status: Abandoned Application

• Current Assignee: Alcon Incorporated
• Original Assignee: Alcon Incorporated
• Inventors: Morgan, Drew, Hong, Xin
• Application Number:
  US11/963,098
• Publication Number:
  US 20090164008A1
• Time in Patent Office: Days
• US Class Current: 623/6.230
• CPC Class Codes: A61F 2/164 Aspheric lenses
• CPC Class Codes: A61F 2/1645 Toric lenses
• CPC Class Codes: A61F 2/1654 Diffractive lenses
• 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 3/06 with cylindrical or toric faces
• CPC Class Codes: G02B 3/08 with discontinuous faces, e.g. Fresnel lens diffractive Fresnel lenses G02B5/1876
• CPC Class Codes: G02B 5/1876 Diffractive Fresnel lenses; Zone plates; Kinoforms G02B5/1842, G02B5/1847 take precedence; optical systems having diffractive correction means G02B27/0037; Fresnel lenses operating by refraction G02B3/08
• CPC Class Codes: Y10T 82/10 Process of turning
• CPC Class Codes: Y10T 82/16016 Processes
• CPC Class Codes: Y10T 82/2502 with program control

Abstract

In one aspect, the present invention provides an intraocular lens (IOL) that includes an optic comprising an anterior surface, a posterior surface, and a plurality of diffractive zones disposed on one of those surfaces. The surface having the diffractive zones has a profile characterized by a combination of aspheric and toric components.

Claims

1. An intraocular lens (IOL), comprising

an optic comprising an anterior surface and a posterior surface,

a plurality of diffractive zones disposed on one of said surfaces,

wherein said surface having the diffractive zones exhibits a base profile characterized by a combination of asphericity and toricity.

2. The IOL of claim 1, wherein said optic provides a far focus and a near focus.

3. The IOL of claim 2, wherein said far focus provides an optical power in a range of about 16 D to about 32 D.

4. The IOL of claim 3, wherein said near focus provides an add power in a range of about 1 D to about 6 D.

5. The IOL of claim 1, wherein said anterior surface comprises said diffractive structures and said asphericity and toricity.

6. The IOL of claim 1, wherein a profile of said surface is characterized by the following relation:

sag(R_avrg,r,θ

)=diffractive(R_ave,r)+toric(R_ave,r,θ

)+asph(R_ave,r),

wherein,

sag represents a sag of the surface along an optical axis of the optic at a radial distance r from a center of the surface at a meridian angle θ

, where R_avrg represents a base radius of curvature of average meridian, and

wherein,

diffractive(R_avrg,r)=z_rad−

√

{square root over (R_rad²−

r²)},

wherein,

z_rad and R_rad denote, respectively, a radius of curvature of a diffractive zone extending through the radial distance r and an axial location of a curvature center of that zone, and

wherein,

7. The IOL of claim 6, wherein z_rad is defined in a Cartesian coordinate (x,y,z), where z is along the optical axis, in accordance with the following relation:

8. The IOL of claim 7, wherein R_rad is defined in the Cartesian coordinates in accordance with the following relation:

R_rad=√

{square root over ((z_in−

z_rad)²+x_in²)}.

9. The IOL of claim 8, wherein a magnitude of R_avrg is in a range of about 12 mm to about 120 mm.

10. The IOL of claim 9, wherein a magnitude of c_x is in a range of about 0.008 mm⁻

1 to about 0.08 mm<sup>−

1</sup> and a magnitude of c_y is in a range of about 0.008 mm<sup>−

1</sup> about 0.08 mm<sup>−

1</sup>.

11. The IOL of claim 10, wherein kx is in a range of about −

3000 to about −

12 and k_y is in a range of about −

3000 to about −

12.

12. The IOL of claim 11, wherein k is in range of about −

3000 to about −

12.

13. The IOL of claim 1, wherein said diffractive zones comprise a plurality of diffractive structures separated from one another by a plurality of step heights.

14. The IOL of claim 13, wherein a radius of curvature of a diffractive zone along a meridian characterized by an angle θ

(R_d^θ

) and a radius of curvature of a base profile associated with that diffractive zone (R_b^θ

) are related in accordance with the following relation;

15. The IOL of claim 14, wherein said Constant is in a range of about 0 D to about 4 D.

16. The IOL of claim 1, wherein said anterior surface includes said diffractive zones.

17. The IOL of claim 16, wherein said posterior surface exhibits a spherical profile.

18. A diffractive ophthalmic lens, comprising

an optic having an anterior surface and a posterior surface,

wherein at least one of said surfaces exhibits a profile characterized by a combination of diffractive, aspheric and toric components.

19. The ophthalmic lens of claim 18, wherein said lens provides a far-focus optical power in a range of about 16 D to about 32 D.

20. The ophthalmic lens of claim 19, wherein said lens provides a near-focus power characterized by an add power in a range of about 1 D to about 6 D.