The invention relates to a variable focus lens (10), comprising a rigid ring (22), a flexible membrane (20) attached to the front surface of the ring, a rigid transparent front cover (40), attached to the flexible membrane (50), and a rigid rear cover (20) on the rear surface of the ring (22). A cavity (60) is formed between the flexible membrane (50) and the rear cover (20), and the cavity is filled with a liquid. The amount of liquid in the cavity can be varied to vary the curvature of the flexible membrane and so vary the optical characteristics of the lens. The rear cover can be integral with the ring, or formed separately. Further, a second flexible membrane can be positioned between the rear cover and the ring. The various parts of the lens can be held together by adhesive.