Patent ID: 8317323

Claim:
A method of designing a soft contact lens, said lens having a central optic zone and with a peripheral zone around the central optic zone; the method comprising the steps of: (a) defining a back surface of the lens which is a satisfactory fit to the surface of a subject's cornea; (b) defining a front surface of the lens over at least the central optic zone, which surface is selected so as to ameliorate the subject's vision defects; (c) checking that the lens meets a desired range of thickness values at one or more selected parts of the lens and, if not, recalculating the front surface over at least the central optic zone so as to meet said desired thickness value range, wherein the lens is to be made of a substance having a Young's modulus in the range 0.08 to 0.40 MPa, and wherein the junction thickness of the lens is in the range 0.15-0.40 mm, and further comprising (d) defining one or more positions or loci within the peripheral zone of the lens, and adjusting the sagittal depth of the lens at the one or more defined positions or loci so as to improve the fit of the peripheral zone of the lens to the subject's cornea.