VARIABLE FOCUS LENS AND SPECTACLES

摘要

A variable focus lens (10) comprises a ring (20) with a front surface and a rear surface. A flexible membrane (40) is held between the front surface of the ring and a generally rigid transparent front cover (50), and a rear cover (60) is mounted on the rear surface of the ring, such that a cavity formed between the flexible membrane and the rear cover can be filled with a liquid. The amount of fluid in the cavity can be varied to vary the curvature of the flexible membrane and so vary the optical characteristics of the lens. The ring is provided with an integral hollow extension (22), whose hollow interior (24) communicates with the cavity and forms a liquid reservoir for the variable focus lens (10). The invention also extends to spectacles using the lens.