Description of the Active Optics manufacturing process. 1: A convex blank with radial thickness distribution is supported on a circular ring. 2: The blank is warped into the exact inverse of the final aspherical shape using a back pressure. 3: The spherical grinding/polishing removes the material corresponding to the deformation. 4: After removal of the loads, the blank turns back into its stress-free state and the polished surface becomes aspherical.