Method of optimizing a support material for an operation of surfacing of a lens blank

A method of preparing a lens blank and surfacing said lens blank, the method comprising:

• determining, by a processor, a surfaced lens shape based on input data;
• based on the determined surfaced lens shape, determining, by the processor, a maximum diameter of a support material shape having a circular periphery as a function of a predetermined maximum thickness defining the maximum thickness of a support material configured to define the support material shape, which is allowed to be cut into during the surfacing of the lens blank and a function of an overhang-related maximum radius determined based on a support overhang corresponding to a radial distance between an edge of the surfaced lens shape and an edge of the support material, the overhang-related maximum radius being determined based on the maximum radius of the surfaced lens shape, a predetermined minimum support overhang, and a support material tolerance margin related to a precision with which the support material is formed;
• choosing, by the processor, a diameter for the support material shape less than or equal to said determined maximum diameter;
• preparing a support that includes a support base and the support material via which the lens blank is to be fastened to the support base, the support material defining the determined support material shape having a diameter corresponding to the chosen diameter;
• fastening the lens blank to the prepared support via the support material;
• and
• surfacing the lens with a generator, the surfacing transforming the lens blank into a surfaced lens having the determined surfaced lens shape at the end thereof.