Patent ID: 8608312
Filing Date: 2013-12-17
Classification: G02C

Abstract:
1. A method for determining an aspherization layer for an ophthalmic lens for a wearer having a prescribed astigmatism and a prescribed power, comprising the following steps: providing a semi-finished lens with an unknown aspheric surface supported by a front surface or a rear surface of the semi-finished lens, the semi-finished lens having known information; choosing a generic surface having known sphere and cylinder values at each point, the generic surface being any surface chosen based on the known information of the semi-finished lens; creating a target fictitious lens having a front surface that is the generic surface and a rear surface, the target fictitious lens defining optical targets for each viewing direction from the prescribed astigmatism and the prescribed power; creating a current fictitious lens, the current fictitious lens initially being an initial fictitious test lens having a front surface that is the generic surface and a rear surface; optimizing the current fictitious lens by modulating the rear surface of the current fictitious lens to achieve the optical targets of the target fictitious lens for each viewing direction; and determining a complex aspherization layer corresponding to the rear surface of the optimized current fictitious lens from which the rear surface of the initial fictitious test lens is subtracted, the complex aspherization layer for use in determining the ophthalmic lens.