Abstract: An improved ophthalmic lens and method of making same, said lens being formed of refractive material having two refractive surfaces one of which is divided into first and second viewing zones intended respectively for distant vision and near vision. The first viewing zone of the lens occupies substantially the upper half of said one surface and may be spherical or it may be an aspheric surface of revolution. The second zone of the lens occupies the lower portion of said one surface and is uniquely configured to markedly reduce blur and distortion. The method of the invention provides a novel and superior technique for smoothly connecting the surface between the distance and near viewing portions of the lens. The lens produced by the method is unique in that blur and distortion in the portion of the lens predominently used by the wearer is substantially eliminated.

Abstract: An improved ophthalmic lens made of refractive material and having varying focal length, said lens having two refractive surfaces one of which is divided into first, second and third viewing zones intended respectively for distant vision, intermediate vision and near vision. The first viewing zone of the lens occupies substantially the upper half of said one surface and has a substantially constant curvature providing a substantially constant focal length for distant vision. The third zone of the lens occupies the lower central portion of said one surface and has a substantially constant curvature providing a substantially constant focal length for near vision. The second zone of the lens lies between the first and third zones and has a varying curvature providing a varying focal length, the curvature of the second zone varying progressively from the substantially constant curvature of the third zone.

Abstract: An all-in-one instrument for use in checking and calibrating a multiplicity of different tools and measuring devices of the type commonly employed in the lens manufacturing industry. Due to the design of the device, the single instrument can be used for precisely checking, cross-checking and calibrating numerous devices including lens clocks, lens meters, surfacing laps and calipers.