METHOD FOR AUTOMATED IN-LINE DETERMINATION OF CENTER THICKNESS OF AN OPHTHALMIC LENS

摘要

A method for automated in-line determination of the center thickness of an ophthalmic lens comprises the steps of providing an inspection cuvette (2) comprising an optically transparent bottom (21) having a concave inner surface (210) and containing the lens immersed in a liquid, and providing an interferometer comprising a light source and a focusing probe (30) focusing light coming from the light source to a set position (310) of the lens. Focusing probe (30) also directs light reflected at the boundary between the back surface of the lens and the liquid as well as light reflected at the boundary between the front surface of the lens and the liquid or at the boundary between the front surface of the lens and the concave inner surface (210) to a detector of the interferometer. The center thickness of the lens is determined using the light reflected at the respective boundary at the back surface and at the front surface of the lens.