Patent ID: 8864307

Claim:
A soft contact lens for treating ametropia, comprising the following circumferential zones: (a) an optical zone in the center of the lens having a back curvature defined by a first optical base curve, a front curvature defined by a first optical front curve, a minimum axial thickness, and a maximum axial thickness, wherein the minimum axial thickness of the optical zone is at the center of the optical zone and the thickness of the optical zone increases toward an outer edge of the optical zone; (b) a pressure control zone extending radially outwardly from the optical zone, the pressure control zone having a back curvature defined by a pressure control base curve, a front curvature defined by pressure control front curve, a minimum axial thickness, and a maximum axial thickness, wherein the maximum axial thickness of the pressure control zone is in a radially central portion of the pressure control zone and the axial thickness of the pressure control zone decreases radially from the central portion of the pressure control zone toward the optical zone and toward the peripheral zone; and (c) an alignment zone extending radially outwardly from the pressure control zone, the alignment zone having a back curvature defined by alignment base curve, a front curvature defined by alignment front curve, a minimum axial thickness, and a maximum axial thickness, wherein the minimum axial thickness of the alignment zone is in a radially central portion of the alignment zone and the axial thickness of the alignment zone increases from the central portion of the alignment zone toward the pressure control zone; wherein the maximum axial thickness of the pressure control zone is greater than the maximum axial thickness of the optical zone and the maximum axial thickness of the alignment zone, and wherein the contact lens is pliable and is made from a material containing between 20% and 70% water.