A method of manufacturing an optical lens, the method comprising the steps of blocking a lens member at a first position on a blocker; determining the first position of the lens member with respect to the blocker; comparing the first position of the lens member with a predetermined position in order to determine a positioning error between the first position and the predetermined position; determining a surface position of the surface to be manufactured with respect to the blocker according to the positioning error; and configuring operational parameters of a lens manufacturing tool in order to manufacture a surface according to the determined surface position such that the desired optical properties of the optical lens are respected. The invention further relates to an apparatus for manufacturing an optical lens.