Progressive multifocal contact lens suitable for presbyopia compensation

摘要

The progression of the optical power of the lens comprises a first tract (a) that descends rapidly to the base dioptric power and in which the lens functions for near vision; a short second tract (b) that remains substantially at the level of the base dioptric power and in which the lens functions for far vision; and a third tract (c) consisting of a first progressively rising part (c') and a constant second part (c'') and in which the lens functions progressively for intermediate distance in the first part and in a constant manner for near vision in the second part.