US Patent 8388130 Non-deforming contact lens

The present invention is directed to a non-deforming contact lens comprising a central zone and a peripheral zone, wherein the central zone has a radius of curvature approximately equivalent to a central curvature of an underlying cornea, wherein the central zone is progressively aspheric with an initial zone approximately elliptical and then progressing to a parabolic shape and then to a hyperbolic shape. The peripheral zone reverses the progressive asphericity of the central zone, and includes a terminating local radius that is shorter than a radius at a junction of the central zone and the peripheral zone.