Blanks for making prescription eyeglass lenses

摘要

In a method and apparatus for making a lens for a pair of prescription eyeglasses a lens blank is shaped and finished on one of its major surfaces through the use of a machine controlled by the prescription information and with a new expendable lap being made each time a new lens is wanted. A machine for cutting a lens blank and/or a lap blank is controlled in three axes by a set of point data related to and obtained in response to the input into the control system for the machine of prescription information. Lap blanks and lens blanks usable by the machine are distinguishable from one another by each lap blank, or each lens blank, having an anomaly, such as a piece of magnetic material detectable by a sensor or the blank is rotated by the machine.