Patent ID: 6857740

Claim:
A contact lens, comprising: a contact lens body having a generally spherical base curvature with a convex anterior face, a concave posterior face, and a peripheral edge therebetween with a peripheral zone being defined adjacent the peripheral edge of the anterior face that is tapered thinner toward the peripheral edge of the lens body, an optic zone being defined generally in the middle of the lens body, the body having a thickness between the anterior face and the posterior face and being non-axi-symmetric so as to define a superior edge and an inferior edge, with a vertical meridian being defined from the superior edge toward the inferior edge and a horizontal meridian being defined perpendicular thereto; an inner zone on the anterior face circumscribed by the peripheral zone and surrounding the optic zone, wherein the inner zone comprises a superior portion between the optic zone and the superior extent of the inner zone, an inferior portion between the optic zone and the inferior extent of the inner zone, and an intermediate portion between the superior and inferior portions; a ballast portion defined on the anterior face radially inward from the peripheral zone of the lens body wherein in at least a part of the ballast portion the thickness of the lens body increases parallel to the vertical meridian from the superior edge toward the inferior edge, the ballast portion including a series of consecutive horizontal cross-sections exclusive of the optic zone each having a substantially uniform thickness; and wherein the ballast portion is defined within one or more of the superior, intermediate, and inferior portions and spans a distance along the vertical meridian of at least a fraction of the smallest dimension of the superior, intermediate, and inferior portions as measured along the vertical meridian.