Friction stabilized contact lenses
A contact lens incorporating one or more surface modified zones on the anterior surface of the lens may be utilized to generate a friction driven rotational force when the upper and/or lower eyelids pass over the one or more regions during blinking. A small difference in the coefficient of friction between the modified and unmodified regions of the lens may result in an equivalent rotational force to that of a thickness gradient lens. This small difference in the coefficient of friction produces a means to orient and stabilize the contact lens on eye.
1. A friction stabilization ophthalmic device comprising:
a contact lens having an anterior surface and a posterior surface and requiring rotational stability on eye, the contact lens being formed from a first lens material; and
one or more surface modified zones incorporated at least one of into or onto the anterior surface of the contact lens, the one or more surface modified zones being configured to facilitate alignment, via rotation, of the contact lens on the eye at a rotational angle for optimal visual acuity, the one or more surface modified zones comprising a second lens material with a coefficient of friction that is 0.1 or greater relative to the first lens material of the remaining portion of the contact lens.
2. The ophthalmic device according to claim 1 , wherein the first lens material comprises a silicone hydrogel.
3. The ophthalmic device according to claim 1 , further comprising two surface modified zones.
4. The ophthalmic device according to claim 3 , wherein the two surface modified zones are symmetrically arranged 180 degrees apart about a vertical axis passing through a geometric center of the lens.
5. The ophthalmic device according to claim 3 , wherein the two surface modified zones are each symmetrically arranged about a horizontal axis passing through a geometric center of the lens.