Method and apparatus of forming a translating multifocal contact lens having a lower-lid contact surface
The present invention discloses a translating multifocal contact lens including one or both of multiple Optic Zones and a lower-lid contact surface, and method steps and apparatus for implementing the same. In preferred embodiments, a translating multifocal lens may be Free-formed comprising a lower-lid contact surface capable of limiting the amount of translation of a lens across a surface of an eye when an eye changes from one Optic Zone to another.
1. A translating multifocal contact lens comprising:
an anterior surface comprising an arcuate shape;
a posterior surface comprising an arcuate shape, wherein said posterior surface is opposite of said anterior surface and wherein said posterior surface and said anterior surface meet each other at a Lens Edge;
an optical-power region to provide vision correction for an eye of a user wherein said optical-power region comprises multiple Optic Zones; and
first and second non-contiguous Stabilization Zones positioned external to and on opposite lateral sides respectively of the optical-power region to provide for both vertical stability for the lens and rotational stability for the lens, the first and second Stabilization Zones each extending in a longitudinal direction between a first end substantially adjacent to a lower portion of the Lens Edge that extends beneath the optical-power region and a second end located above the center of the optical-power region, wherein the first end is wider than the second end;
wherein the first end of the first and second Stabilization Zones forms a lower-lid contact surface that limits the amount of lens translocation upon the eye of the user when the user changes direction of vision and the user's line of sight moves from at least one Optic Zone to another said Optic Zone to thereby provide vertical stability for the lens;
wherein said contact lens is a free form lens.
2. The translating contact lens of claim 1 wherein the Stabilization Zone comprises a geometric shape defined by one or both of points and lines with at least one curve to define a surface.
3. The translating contact lens of claim 1 wherein the Stabilization Zone comprises an arced segment of hydrogel material with an angular width between 0° to 180°.
4. The translating contact lens of claim 1 wherein the Stabilization Zone comprises a width (w) of 5 mm or less, and a peak height (ht) of 1 mm or less.
5. The translating contact lens of claim 1 wherein the optical-power region comprises a spherical boundary shape.
6. The translating contact lens of claim 1 wherein the optical-power region comprises a non-spherical boundary shape.
7. The translating contact lens of claim 1 wherein the optical-power region comprises one or more of a far-power Optic Zone, an intermediate-power Optic Zone, and a near-power Optic Zone.
8. The translating contact lens of claim 7 wherein at least one said Optic Zone comprises a geometric shape defined by one or both of points and lines with at least one curve to define a surface.
9. The translating contact lens of claim 1 wherein the lower-lid contact surface comprises a contiguous, inward extension of the anterior surface portion that extends laterally across said anterior lens surface.
10. The translating contact lens of claim 9 wherein the lower-lid contact surface comprises a geometric shape defined by one or both of points and lines with at least one curve to define a surface.