Patent ID: 6270220
Filing Date: 2001-08-07
Classification: G02B,G02C

Abstract:
A multifocal lens having far and near vision zones, the multifocal lens comprising a combination of a progressive addition lens and a diffractive element wherein:(a) said progressive addition lens is a substrate carrying said diffractive element, which is in the form of a modulation on the surface of the substrate:said substrate has refractive power distribution defining far and near vision zones, selected in accordance with respective prescribed values of optical power required for a patient's eye at the patient's distance reading vision, and an intermediate transition region between the far and near vision zones; and(b) said modulation produces locally variable optical power addition to the optical power of the substrate, said locally variable optical power addition being maximal within said intermediate transition region and decreasing gradually towards the far and near vision zones of the substrate, said far and near vision zones of the multifocal lens being thereby wider than said far and near vision zones of the substrate.