Mandrel for use in the machining of ophthalmic lenses

A mandrel and an ophthalmic lens member blank to be machined, the mandrel holding the ophthalmic lens member blank, the ophthalmic lens member blank having a surface comprising a curved surface region and a planar surface region, the mandrel having a front surface receiving the ophthalmic lens member blank to be machined;

• the front surface comprising;
• a planar surface region of the mandrel abutting the planar surface region of the ophthalmic lens member blank;
• a curved surface region of the mandrel with wax applied thereto, the ophthalmic lens member blank placed onto the wax;
• and
• a drainage channel extending along at least a portion of the boundary between the curved surface region of the mandrel and the planar surface region of the mandrel such that wax applied to the curved surface region flows into the drainage channel.