Abstract: A tool is disclosed for accurately and rapidly finishing optical surfaces. The tool has a plurality of lapping buttons attached to its face for contacting the optical surface to be finished. The lapping buttons are held to the surface of the workpiece by a suction established between the tool and the workpiece. The suction force existing between the tool and the workpiece is monitored by a controller and may be selectively changed as the tool is moved across the surface of the workpiece during lapping operations. As the tool is moved toward the edge of a workpiece, the vacuum applied to those buttons approaching the edge of the workpiece is increased to achieve desired rate of material removal. The invention permits selective control of the amount of vacuum applied to each lapping button to permit maximum grinding and/or polishing to be achieved. The disclosed tool permits the use of a thinner facesheet in an optical system while permitting a complex surface geometry to be ground into the facesheet.

Abstract: Method and apparatus for manufacturing glass progressive power lenses. The lenses are manufactured by a vacuum forming technique in which a glass lens is placed upon a forming block, heated to its softening point, and then forced to sag against and assume the shape of the forming block surface by the creation of a vacuum between the lens blank and the block surface. The forming block is provided with a plurality of apertures through which the vacuum is drawn and these apertures are positioned so as to ensure the maintenance of an adequate pressure differential between the two surfaces of the lens blank as it sags in a wave-like manner from its center towards its periphery.

Abstract: A progressively variable focal power ophthalmic lens. The lens has a unique geometry which allows the correction of distortion of horizontal and vertical lines to be retained below detectable levels in the temporal peripheral zone of the lens after the lens is rotated to accommodate the left or right eye. In addition, the geometry further allows the minimization of the astigmatic aberration in the area of the peripheral zone adjacent to the distance portion and the elimination of the astigmatic aberration in the lower part of the temporal peripheral zone.

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.