Contact lens

• US 5,953,098 A
• Filed: 07/20/1998
• Issued: 09/14/1999
• Est. Priority Date: 12/30/1996
• Status: Expired due to Term

• Current Assignee: Scientific Optics Incorporated
• Original Assignee: Scientific Optics Incorporated
• Inventors: Lieberman, David M, Grierson, Jon
• Primary Examiner(s): Sugarman, Scott J.
• Application Number:
  US09/119,617
• Time in Patent Office: 421 Days
• Field of Search: 351/160 R, 351/160 H, 351/161, 351/162, 351/177
• US Class Current: 351/160.00R
• CPC Class Codes: G02C 7/041 bifocal; multifocal
• CPC Class Codes: G02C 7/047 Contact lens fitting; Contact lenses for orthokeratology; Contact lenses for specially shaped corneae

Abstract

A contact lens for use with an asymmetric aspherical cornea. The lens includes an anterior surface, a posterior surface and a base. The posterior and anterior surfaces each include a center optical portion and an outer peripheral corneal portion. The posterior surface is divided into a plurality of local surface segments by a plurality of radially extending boundaries that originate from a common center point on the posterior surface of the lens. Each of the local surface segments conforms to the shape of a corresponding local surface portion of the cornea that lies under the respective lens local surface segment when the lens is worn on the eye.

Claims

1. A contact lens for use with an asymmetric aspherical cornea, said lens comprising:

an anterior surface, a posterior surface and a base, said posterior and anterior surfaces each comprising a center optical portion and an outer peripheral corneal portion, said posterior surface being divided into a plurality of local surface segments by a plurality of radially extending boundaries that originate from a common center point on said posterior surface of the lens, local surface segments on at least the outer peripheral corneal portion conforming to the shape of a corresponding local surface portion of the original asymmetric aspherical cornea that lies under said respective lens local surface segment when the lens is worn on the eye.

2. The lens of claim 1, wherein said lens local surface segments are disposed in said center optical portion.

3. The lens of claim 2, wherein said lens local surface segments comprise at least four segments.

4. The lens of claim 3, wherein said lens local surface segments comprise at least twenty-four segments.

5. The lens of claim 2, wherein said anterior surface is divided into a plurality of local surface segments by a plurality of radially extending boundaries that originate from a common center point on said anterior surface of the lens.

6. The lens of claim 5, wherein said posterior surface and said anterior surface local surface segments are disposed in said center optical portion.

7. The lens of claim 6, wherein said lens local surface segments comprise at least four segments on said posterior surface and at least four segments on said anterior surface.

8. The lens of claim 7, wherein said lens local surface segments comprise at least twenty-four segments on said posterior surface and at least twenty-four segments on said anterior surface.

9. The lens of claim 1, wherein said posterior surface of said outer peripheral cornea portion being divided into a plurality of local surface segments by a plurality of radially extending boundaries that originate from a common center point on said posterior surface of the lens, each of said local surface segments disposed in said outer peripheral cornea portion asymmetrically and aspherically matching a corresponding portion of the cornea that lies under said respective lens local surface segment when the lens is worn on the eye.

10. The lens of claim 9, wherein said lens local surface segments disposed in said outer peripheral cornea portion comprise at least four segments.

11. The lens of claim 10, wherein said lens local surface segments disposed in said outer peripheral cornea portion comprise at least twenty-four segments.

12. The lens of claim 11, wherein said lens local surface segments disposed in said outer peripheral cornea portion comprise at least seventy-two segments.

13. The lens of claim 2, wherein said center optical portion comprises an inner central portion and an inner peripheral portion, said posterior and anterior surfaces of said inner central portion and said inner peripheral portion each being divided into a plurality of local surface segments by said plurality of radially extending boundaries that originate from said common center point on said respective posterior and anterior surfaces.

14. The lens of claim 13, wherein said radially extending boundaries in said posterior surface of said inner central portion are arcuate curves that conform to the shape of the cornea which lies under said radially extending boundaries when the lens is worn on the eye.

15. The lens of claim 14, wherein said radially extending boundaries in said posterior surface of said inner peripheral portion are arcuate curves that conform to the shape of the cornea which lies under said radially extending boundaries when the lens is worn on the eye.

16. The lens of claim 9, wherein said radially extending boundaries in said posterior surface of said outer peripheral corneal portion are splines that match the shape of the cornea which lies under said radially extending boundaries when the lens is worn on the eye.

17. The lens of claim 15, wherein said lens local surface segments disposed on said posterior surface of said inner central potion are a plurality of curve driven surfaces.

19. The lens of claim 9, wherein said lens local surface segments disposed on said posterior surface of posterior surface of said outer peripheral portion are a plurality of curve mesh surfaces.

20. The lens of claim 1, wherein said posterior and anterior surfaces of said lens each comprise an outer scleral portion.

21. The lens of claim 1, wherein said anterior surface of said center optical portion being comprised of a central spherically shaped portion and an inner peripheral toric shaped portion.

22. The lens of claim 21, wherein said inner peripheral toric shaped portion has a major and a minor axis that are disposed at an angle of other than 90°

with respect to each other.

23. The lens of claim 22, wherein said central spherically shaped portion is offset with respect to a geometric center of said lens.

24. The lens of claim 1, wherein said center optical portion including a second center portion and an annular portion;

a first refractive power region within at least said second center portion; and

a second refractive power region substantially concentrated in a predetermined location within said annular portion on a nasal side of the lens relative to the eye upon placement on the eye, said second refractive power region being of greater refractive power than said first refractive power region.

25. The lens of claim 24, wherein said second power region is substantially concentrated only in said predetermined location.

26. The lens of claim 25, wherein said predetermined location is disposed on an inferior side of the lens relative to the eye.

27. The lens of claim 1, wherein said anterior surface of said center optical portion is spherical.

28. The lens of claim 1, wherein said anterior surface of said center optical portion is toric.

29. The lens of claim 28, wherein a major and a minor axis of said anterior surface of said center optical portion are disposed at an angle of other than 90 degrees with respect to each other.

30. The lens of claim 1, wherein a center of said lens is disposed over a high point of the cornea when the lens is worn on the eye.

18. The lens of claim 18, wherein said lens local surface segments disposed on said posterior surface of said inner peripheral portion are a plurality of curve mesh surfaces.