Toric lens design
View Patent ↗This invention is related to contact lenses. In particular, the present invention is related to a toric contact lens design with thickness zones in the carrier portion of the lens for increased rotational stability.
1. A toric contact lens design comprising a central optical zone, a vertical meridian, a transition zone surrounding said central optical zone, a carrier extending from said transition zone outward and a plurality of thickness zones in said carrier, wherein the thickness zones are designed to achieve rotational stability; wherein the thickness profile is measured along angular meridians; wherein said plurality of thickness zones further comprises three thickness zones; wherein the second said three thickness zones is symmetrical across the vertical meridian on the sides of said lens design; wherein the slope of the thickness profile of the second zone is a step function.
2. The design of claim 1 , wherein each thickness zone has two boundaries.
3. The design of claim 1 , wherein the first and third of said three thickness zones are at the top and the bottom of said lens design.
4. The design of claim 1 , wherein the boundary between the first zone and second zone is about 15 degrees from the vertical meridian.
5. The design of claim 1 , wherein the boundary between the first and second zone is about 25 degrees from the vertical meridian.
6. The design of claim 1 , wherein the boundary between the first and second zone is about 45 degrees from the vertical meridian.
7. The design of claim 1 , wherein the boundary between the third zone and second zone is about 30 degrees from the vertical meridian.
8. The design of claim 1 , wherein the boundary between the third and second zone is about 60 degrees from the vertical meridian.
9. The design of claim 1 , wherein the thickness profile of the second zone increases from its upper boundary to its lower boundary.
10. The design of claim 1 , wherein there is a relatively consistent thickness section at each angular meridian.
11. The design of claim 1 , wherein width of a relatively consistent thickness is at least 30% of the zone width.
12. The design of claim 1 , wherein a thickness change is equal or less than 10% of the maximum thickness at the meridian.
13. The design of claim 1 , wherein a thickness range from the upper boundary to the lower boundary of the second zone is about 0.065 mm to about 0.45 mm.
14. The design of claim 1 , wherein a thickness range from the upper boundary to the lower boundary of the second zone is about 0.140 mm to about 0.340 mm.
15. The design of claim 1 , wherein the same carrier may be used for different optical zones on different lenses.
16. The lens created by claim 1 .
17. The lens of claim 16 , wherein said lens is a soft lens.
18. The design of claim 1 , further comprising a second transition zone at the edge of the lens.
19. The design of claim 1 , wherein said design provides an annular region.
20. A toric contact lens design comprising a central optical zone, a carrier extending from said central optical zone outward and a plurality of thickness zones in said carrier, wherein the thickness zones are designed to achieve rotational stability; wherein said plurality of thickness zones is three thickness zones; wherein the slope of the thickness profile of the second zone is a step function.
21. The design of claim 20 , wherein each thickness zone has two boundaries.
22. The design of claim 20 , wherein the thickness profile is measured along angular meridians.
23. The design of claim 20 , wherein the second of said three thickness zones is symmetrical across the vertical meridian on the sides of said lens design.
24. The design of claim 20 , wherein the first and third of said three thickness zones are at the top and the bottom of said lens design.
25. The design of claim 20 , wherein the boundary between the first zone and second zone is about 15 degrees from the vertical meridian.
26. The design of claim 20 , wherein the boundary between the first and second zone is about 25 degrees from the vertical meridian.
27. The design of claim 20 , wherein the boundary between the first and second zone is about 45 degrees from the vertical meridian.
28. The design of claim 20 , wherein the thickness profile of the second zone increases from its upper boundary to its lower boundary.
29. The design of claim 20 , wherein a thickness range from the upper boundary to the lower boundary of the second section is about 0.065 mm to about 0.45 mm.
30. The design of claim 20 , wherein a thickness range from the upper boundary to the lower boundary of the second section is about 0.140 mm to about 0.340 mm.
31. The design of claim 20 , wherein the same carrier may be used for different optical zones on different lenses.
32. The lens created by claim 20 .
33. The lens of claim 32 , wherein said lens is a soft lens.
34. The design of claim 20 , further comprising a transition zone at the edge of the lens.