Optical Properties of Spectacle Lenses Computed by Surfaces Differential Quantities

The surface optical properties of an ophthalmic lens are closely related to curvature parameters and consequently they can be derived by the geometric characterization of the lens surface. Adopting this approach it is possible to verify a spectacle lens by contact probe measurements without light transmission based instruments. Moreover, this method can be applied in the design stage to verify the surface optical properties of complex surface geometries as in progressive lens design. In this work, in order to derive the optical properties of a spectacle lens, a method based on quadratic fitting to assess the curvature properties of discrete surfaces is proposed. The procedure has been validated on several discrete surfaces, and subsequently error fitting functions were derived.