Translating presbyopic contact lens
Lenses for correcting presbyopia are translating, multifocal contact lenses with pseudotruncations which are asymmetric about the vertical meridian.
1. A translating presbyopic contact lens comprising an optical zone, a peripheral zone around the optical zone and a pseudotruncation which is asymmetric and rotated at least one of up or down about the vertical meridian, wherein the pseudotruncation comprises an elongated, arcuate thickened portion in the lens, peripheral to the optical zone but inside of an edge of the lens.
2. The contact lens of claim 1 wherein the pseudotruncation is rotated nasally up by between 1 to 15 degrees.
3. The contact lens of claim 1 wherein the pseudotruncation is rotated nasally up by between about 7 to 8 degrees.
4. The contact lens of claim 1 wherein the pseudotruncation is rotated nasally down by between about 1 to 10 degrees.
5. The contact lens of claim 1 wherein the pseudotruncation and optical zone are rotationally aligned substantially the same amount.
6. The contact lens of claim 1 wherein the pseudotruncation and optical zone are not rotationally aligned substantially at the same amount.
7. The contact lens of claim 1 wherein the optical zone is inset horizontally nasalward.
8. The contact lens of claim 1 wherein the optical zone is rotated nasally up.
9. The contact lens of claim 1 wherein the optical zone is inset horizontally nasalward and rotated nasally up.
10. The contact lens of claim 1 wherein the optical zone is inset horizontally nasalward and rotated nasally up and further moved up.
11. The contact lens of claim 1 wherein the pseudotruncation comprises a single elevated zone.
12. The contact lens of claim 1 wherein the pseudotruncation comprises more than one elevated zone.
13. The contact lens of claim 1 wherein the angular subtense of the pseudotruncation when it is 80% of its maximum thickness, is between 40 and 100 degrees circumferentially around the lens.
14. The contact lens of claim 1 wherein the pseudotruncation varies in height or circumferential angular subtense with changes in refractive prescription.
15. The contact lens of claim 1 wherein the pseudotruncation varies in height or circumferential angular subtense on a basis of data from an individual wearer.
16. The contact lens of claim 1 wherein the pseudotruncation varies in height or circumferential angular subtense on a basis of data from a population, sub-population, or group.
17. The contact lens of claim 1 wherein the radial position of the peak thickness value of the pseudotruncation at any meridian around the lens is substantially constant, the arc being a portion of a concentric circle about the lens center.
18. The contact lens of claim 1 wherein the radial position of the peak thickness value of the pseudotruncation at any meridian around the lens is variable, the arc not being a portion of a concentric circle about the lens center.
19. The contact lens of claim 1 wherein the outer circumference of the lens is substantially circular, or concentric with a constant radius about the lens center.
20. The contact lens of claim 1 wherein the outer circumference of the lens is not circular, and not concentric about the lens center.
21. The contact lens of claim 1 wherein the width of the bevel portion is between about 50.mu. to about 500.mu.
22. The contact lens of claim 1 wherein the position of the bevel flange junction is between about 5 to about 7 mm.
23. The contact lens of claim 1 wherein the maximum radial thickness of the lenticular bevel junction is between about 300.mu. to about 600.mu.
24. The contact lens of claim 1 wherein the thickness of the bevel flange junction is between about 75.mu. to about 250.mu.
25. The contact lens of claim 1 wherein, when said lens is worn on eye, the thickened portion engages with the lower eyelid of the wearer to achieve translation on the eye.