Contact lenses for myopic eyes and methods of treating myopia
A contact lens and a method for treating an eye with myopia is described. The contact lens includes an inner optic zone and an outer optic zone. The outer optic zone includes at least a portion with a first power, selected to correct distance vision. The inner optic zone has a relatively more positive power (an add power). In some embodiments the add power is substantially constant across the inner optic zone. In other embodiments the add power is variable across the inner optic zone. While in some embodiments the inner optic zone has a power designed to substantially eliminate lag of accommodation in the eye with myopia, in other embodiments, the add power may be higher.
1. A contact lens comprising:
an inner optic zone with a diameter that approximates or is less than a pupil diameter;
a transition zone occupying a radial distance of 0.5 mm or less; and
an outer optic zone surrounding the transition zone, the outer optic zone having a variable power and an outer diameter greater than the pupil diameter,
wherein the inner optic zone has an add power portion relative to the power of the outer optic zone of between 0.5 diopters and 4 diopters inclusive, and
wherein the inner optic zone is configured to reduce or eliminate lag of accommodation by said eye when viewing at near distances.
2. The contact lens of claim 1 , wherein the inner optic zone has a diameter between 2 mm and 4 mm.
3. The contact lens of claim 1 , wherein the inner optic zone has a diameter of less than 2 mm.
4. The corneal contact lens of claim 1 , wherein the outer optic zone includes at least a first portion with a third power, relatively more positive than the power of a second portion, different than the first portion, wherein the portion with a third power is distinct from the inner optic zone.
5. The corneal contact lens of claim 4 , wherein the third power is substantially equal to the power in the add power portion.
6. The corneal contact lens of claim 4 , wherein the third power is different to the power in the add power portion.
7. The corneal contact lens of claim 6 , wherein the third power is greater than the power in the add power portion.
8. The corneal contact lens of claim 1 wherein the outer optic zone includes at least two portions with power greater than the power in the add power portion, separated by a portion with the first power.
9. The corneal contact lens of claim 8 , wherein each of said at least two portions have the same power.
10. The corneal contact lens of claim 8 , wherein each of said at least two portions have different powers.
11. The corneal contact lens of claim 10 , wherein the portion with more positive power is located on the contact lens at a greater radial distance than the portion with a lesser power.
12. A method of treating myopia, comprising:
providing a contact lens that includes within an optic zone one or more first portions with a power designed to correct distance vision and one or more second portions with relatively positive power in comparison to the one or more first portions; and
selecting the proportion of the one or more first portions relative to the one or more second portions so as to control the progression of myopia while still maintaining acceptable distance vision,
wherein the one or more second portions has at least one portion occupying a centermost portion of the lens and having a diameter that approximates or is less than a pupil diameter;
wherein the relatively positive power of the one or more second portions is an add power portion relative to the power of the one or more first portions of between 0.5 diopters and 4 diopters inclusive, and
wherein the one or more second portions is configured to reduce or eliminate lag of accommodation by said eye when viewing at near distances.
13. The method of claim 12 comprising selecting the power of at least one of the one or more second portions so as to control the progression of myopia.
14. The method of claim 12 comprising selecting the power of at least one of the second portions to correct lag of accommodation in the eye with myopia.
15. The method of claim 14 , wherein at least two second portions have power selected to correct the lag of accommodation.
16. The method of claim 14 , wherein at least one second portion has a power greater than that required to correct the lag of accommodation.
17. The method of claim 12 , wherein at least one second portion has a power designed to bring to focus images at the peripheral retina on or in front of the retina.
18. The method of claim 12 , wherein at least one second portion has a power designed to bring to focus images at the peripheral retina closer to the retina.