Abstract: A mandrel 1 for holding an ophthalmic lens member blank 16 during machining is disclosed. The mandrel 1 has a front surface 6 for receiving an ophthalmic lens member blank 16 to be machined. The front surface 6 comprises a planar surface region 10; a curved surface region 8; and a drainage channel 12 located between the curved surface region 8 and the planar surface region 10 such that wax applied to the curved surface region 8 flows into the drainage channel 12. A kit of parts comprising such a mandrel 1, a method of mounting an ophthalmic lens member blank 16 for machining, a method of machining an ophthalmic lens member blank 16, an ophthalmic lens produced using the apparatus and a batch of such lenses are also disclosed.

Abstract: An electrically-switchable liquid crystal cell (10) is provided, along with a lens (50) comprising the cell, and methods of manufacturing the cell. The liquid crystal cell (10) includes a diffractive optical element (12) and liquid crystal material (14) switchable between an unmatched state and a matched state. In the unmatched state, the effective refractive index of the liquid crystal material (14) is different from the refractive index of the base material (18) of the diffractive optical element (12). In the matched state, the effective refractive index of the liquid crystal material (14) matches the refractive index of the base material (18). In the matched state the diffractive optical element does not contribute a focal power for the lens. The diffractive optical element (12) has a number of peaks (20) and troughs (30) having rounded corners.

Abstract: A mandrel 1 for holding an ophthalmic lens member blank 16 during machining is disclosed. The mandrel 1 has a front surface 6 for receiving an ophthalmic lens member blank 16 to be machined. The front surface 6 comprises a planar surface region 10; a curved surface region 8; and a drainage channel 12 located between the curved surface region 8 and the planar surface region 10 such that wax applied to the curved surface region 8 flows into the drainage channel 12. A kit of parts comprising such a mandrel 1, a method of mounting an ophthalmic lens member blank 16 for machining, a method of machining an ophthalmic lens member blank 16, an ophthalmic lens produced using the apparatus and a batch of such lenses are also disclosed.

Abstract: A method of manufacturing a contact lens assembly is disclosed. The method comprises bonding an anterior surface of a first lens member to a posterior surface of a second lens member; and then machining an anterior surface of the second lens member and a posterior surface of the first lens member. Lens members are machined to produce datum surfaces on both sides of the member, the datum surfaces defining between them a reference thickness. A contact lens assembly, and contact lens members manufactured using said method are also disclosed.