Patent ID: 8313194

Claim:
A method for selecting base-curves for an ophthalmic lens according to given prescription data and to a chosen design, the method comprising the steps of: providing a base-curve series according to the chosen design consisting of a plurality of base-curves, wherein the base-curved series is a series of semi-finished lens blanks that have front faces that increase incrementally in curvature; providing a target lens according to the prescription data and to the chosen design; calculating the base-curves calculated lenses according to the prescription data so as to calculate an optical system of a lens where the front face of the lens is the front face of the semi-finished lens blank corresponding to said base-curve and the rear face of the lens is optimized so as to fit the wearer's prescription; providing, for at least an optical parameter and/or a geometrical parameter, a threshold value for the difference between the base-curves calculated lenses values and the target lens value of said parameter(s); and determining the list of the base-curves of the base-curve series where said difference for said parameter(s) is less or equal to the selected threshold value(s).