Abstract: The invention relates to an apparatus and method for applying a finishing block to a lens. The apparatus displays an alignment pattern representing characteristics of the lens and includes a visual representation of the allowable tolerance in the position of the optical center of the lens and the prism of the lens. An imaging screen is provided for imaging the alignment pattern and reference data applied to a surface of the lens. The lens is positioned in the apparatus with the pattern and the data aligned. With the lens in this position, a determination is made using the visual representation as to whether the lens is within the allowable tolerance. If this is the case, the apparatus automatically attaches the finishing block to the lens in registration with the reference data.