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 for a myopic eye, the contact lens comprising:
i) an inner lag reduction optic zone with a diameter in the range of 10% to 100% of pupil diameter of the myopic eye viewing near objects;
ii) a transition zone occupying a radial distance of 0.5 mm or less; and
iii) an outer optic zone surrounding the transition zone, the outer optic zone having at least a portion immediately adjacent said transition zone with negative power, said outer optic zone having an outer diameter substantially equal to or greater than the pupil diameter of the myopic eye viewing distant objects;
wherein the inner lag reduction optic zone has add powers that are variable over a plurality of add power portions across the radius of said inner lag reduction optic zone, relative to the said negative power of between 0.5 diopters and 4 diopters inclusive, that reduce or eliminate lag of accommodation by said eye when viewing at near distances.
2. The contact lens of claim 1 , wherein the inner lag reduction optic zone has a diameter in the range of 50% to 100% of pupil diameter of the myopic eye viewing near objects.
3. The contact lens of claim 1 , wherein the inner lag reduction optic zone has a diameter of less than 2 mm.
4. The contact lens of claim 1 , wherein the inner lag reduction optic zone is rotationally symmetric.
5. The contact lens of claim 1 , wherein the outer optic zone having negative power corrects myopia of the myopic eye of a wearer.
6. The contact lens of claim 1 , wherein the outer optic zone is rotationally symmetric.
7. The contact lens of claim 1 , wherein the power profile of the inner lag reduction optic zone equals the power of the outer myopia correction optic zone at the intersection of the inner lag reduction optic zone with the outer myopia correction optic zone.
8. The contact lens of claim 1 , wherein the variable add powers over the plurality of add power portions across the radius of the inner lag reduction optic zone progressively reduces with an increase in diameter.
9. The contact lens of claim 1 , wherein the add power portion of the inner lag reduction optic zone, relative to the said negative power, is between 1.5 diopters and 4 diopters inclusive.
10. The contact lens of claim 1 , wherein the add power portion of the inner lag reduction optic zone, relative to the said negative power, is between 2.6 diopters and 4 diopters inclusive.
11. The contact lens of claim 1 , wherein the contact lens is a soft contact lens or a hard corneal contact lens.
12. The contact lens of claim 1 , wherein the contact lens is a silicone-hydrogel corneal contact lens.
13. The contact lens of claim 1 , wherein the contact lens is a rigid gas permeable corneal contact lens.
14. The contact lens of claim 1 , wherein the contact lens is a corneal on-lay.
15. A method of treating myopia in an eye with lag of accommodation, the method comprising providing a contact lens of claim 1 .
16. A method of treating myopia in an eye with lag of accommodation in a patient in need thereof, the method comprising:
i) providing an initial contact lens with an inner optic zone having a diameter substantially equal to pupil diameter when the patient is viewing near objects and an outer optic zone having an outer diameter substantially equal to or greater than the pupil diameter when the patient is viewing distant objects; and
ii) if the distance vision of the patient is not acceptable, then replacing the initial contact lens with a further contact lens, wherein the further contact lens, relative to the initial contact lens:
a) has a decreased diameter of the inner optic zone; and/or
b) has a decreased or removed relative plus power in the outer optic zone; or
iii) if the distance vision of the patient is acceptable and the patient's myopia is still progressing, then replacing the initial contact lens with a further contact lens, wherein the further contact lens, relative to the initial contact lens:
a) provides an increased proportion of relative plus power;
b) has an increased diameter of the inner optic zone;
c) provides a plus power sub-zone in the outer optic zone; or
d) combinations thereof.
17. The method of claim 16 , wherein the inner optic zone is an inner lag reduction optic zone.
18. The method of claim 17 , wherein the inner lag reduction optic zone has a diameter of less than 2 mm.
19. The method of claim 18 , wherein the add power portion of the inner lag reduction optic zone, relative to the said negative power, is between 1.5 diopters and 4 diopters inclusive.
20. The method of claim 18 , wherein the add power portion of the inner lag reduction optic zone, relative to the said negative power, is between 2.6 diopters and 4 diopters inclusive.