Abstract: A lens having a set of physical features provided on the edge thereof for permitting a set of reference marks to be placed on the lens surface together with an apparatus for applying these physical features to the lens. The apparatus comprises a mold assembly in which the gasket is provided with a plurality of precisely located ridges which define a plurality of corresponding notches formed on the edge of the lens to locate, for example, the distance portion optical center and the 0.degree.-180.degree. lines of a progressive power lens. The gasket is additionally provided with other ridges adapted to mate with grooves formed on the mold member defining the progressive lens surface to ensure proper alignment of that member with the gasket.

Abstract: A teaching device to assist first-time wearers of progressive power eyeglasses in becoming accustomed to their use. The device according to a preferred embodiment, comprises a decal adapted to be attached to the lenses of the glasses, and provided with precisely shaped and positioned cutouts to locate and uncover at least parts of the distance, reading and progressive corridor portions of the lenses.By wearing glasses with the decal affixed to each lens for a couple of hours or so, the wearer can conveniently and easily learn which areas of the lenses to use for particular viewing tasks. After a couple of hours of use, the decals can simply be removed and discarded.