Abstract: A progressive multi-focal lens is provided of the type having a distant viewing zone, a near viewing zone, and a progressive zone therebetween. The surface refractive power increases vertically from an upper portion of the lens to a lower portion as the line of sight scans from a distant view to a near view. Side zones are provided beside the progressive and near viewing zones. The side zones are spheric surfaces, with a dioptric refractive power in accordance with one embodiment being the arithmetic mean value of the refractive power of the near and distant viewing zones. This eliminates astigmatism problems in the side areas and permits normal side sight.

Abstract: Plastic eyeglass lenses and the like are marked with an identifying character or symbol by applying to the surface thereof or dissolving or comelting therein a flourescent dyestuff according to the disclosed method. When the proper amount of flourescent dyestuff is included the lens appears normal in sunlight but is characteristically marked in whole or in part under ultraviolet light depending on the area treated.

Abstract: An improved automatic lens grinding machine and process for shaping lenses to fit any particular glasses frame.The machine includes a recording assembly by which the pattern of a glasses frame which will hold a lens is recorded on a heat or photosensitive substrate. The paper and lens are mounted on a carriage assembly which is movable into and out of a grinding position adjacent a grinding assembly. When positioned in the grinding position, grinding is under control of a scanner assembly and a control circuit.

Abstract: A reflection free optical glass coated, in succession, with a medium refractive index layer, such as CeF.sub.3 or Al.sub.2 O.sub.3, a high refractive index layer such as TiO.sub.2, CeO.sub.2 or ZrO.sub.2 which layer contains a plurality of thin layers of MgF.sub.2 of about 10-100A in thickness uniformly interposed in the high refractive index material at intervals of about one eighth of the design wavelength. The outermost coating of the multi-layer optical glass is a low refractive index layer of MgF.sub.2.

Abstract: An improved automatic lens grinding machine and process for shaping lenses to fit any particular glasses frame.The machine includes a recording assembly by which the pattern of a glasses frame which will hold a lens is recorded on a heat or photosensitive substrate. The paper and lens are mounted on a carriage assembly which is movable into and out of a grinding position adjacent a grinding assembly. When positioned in the grinding position, grinding is under control of a scanner assembly and a control circuit.

Abstract: An auto-refractometer according to this invention comprises a light beam source for producing a measuring ray wherein beams from a pair of invisible infrared ray emission diodes are alternately flickered, and real images of the beams are converged on respective sides of ridges at the output side of a V-shape coincidence prism at positions close to the ray axis thereby reducing the horizontal distance between the beams. A measuring optical system includes a transmitting collimater which projects said measuring ray passing through a vertical slit to permit focusing of a slit image on the retina. A receiving collimator collects beams reflected from the cornea and the retina, and by a semi-transparent mirror, and directs them via a reflection mirror to an interference bar which interferes with the beam from the cornea. A split prism divides the beam received from the retina, and a pair of elements photo-electrically convert the divided beam into electrical outputs.

Abstract: A servo system to permit the lens finishing for example, corresponding to a registered pattern and permit such finishing at desired pressure, etc. for the conveniences of the easy and effective grinding and finishing, in a manner that the detectors supply to the lower and upper limit voltage comparators the detectors outputs, which are then supplied to the logic circuits as well as the outputs for the servo-driving and the outputs from flip-flops, so that the servo motor rotates in normal and/or reverse directions.

Abstract: An automatic digital indicating lens meter is provided with an optical system having a light beam source and a target which reciprocally moves within a certain range along the optical axis, the target having several circular luminous points. An image pickup system including a lens to be inspected, such as a mono-focal point spherical lens or a bi-focal non-spherical point lens, is fixed on the optical axis approximately mating with the luminous centers of a light beam source collimator and a light beam receiving collimator. A photo electric converter is located at the focal plane of the receiving collimator; on an extension of said optical axis. An electric circuit analyses by scanning lines, the images detected by said electric light converter as time series signals and counts the position when the time band width of the brightness signal becomes minimum in the course of movement of the target.