Abstract: A method for generating a virtual entity of an ophthalmic lens blank in a computer environment and for using this entity to monitor and control a lens generation process. The method comprises the steps of analyzing an image of a lens blank, measuring a first surface of a lens blank, probing a second surface, and locating both surfaces and the contour of the lens blank in a spatial coordinate system. These data are used to generate a virtual entity that is a precise representation of the lens blank. The virtual entity is used throughout the lens generation process for blocking the lens, for calculating and selecting lens orientation, skewing, prism, tool angles and ideal tool paths that produce best lens quality.

Abstract: The apparatus comprises a base having orthogonal horizontal longitudinal axis, horizontal transversal axis and vertical axis, and a tool spindle having a motor and a lens surfacing tool mounted on a rotatable arbour of the motor. The apparatus also comprises a lens holder having a chuck for retaining an ophthalmic lens with a perimeter thereof defining a plane being substantially perpendicular to the longitudinal axis. A first linear slide is affixed to the base and has a first movable support and a first actuator for moving the first movable support along the longitudinal axis. A second linear slide is also affixed to the base and has a second movable support supporting the lens holder and a second actuator for moving the second movable support and the lens holder along the transversal axis. A rotary table is affixed to the first movable support and supports the tool spindle. The rotary table has a third actuator for rotating the rotary table about the vertical axis.