Abstract: A blocking piece for vacuum blocking a lens blank is disclosed. The blocking piece includes a blank contacting element formed of a rigid fluid-permeable material having an upper surface for contacting the lens blank. The blocking piece further includes a support element having an upper part tightly enclosing the blank contacting element on a peripheral surface of the blank contacting element and a lower part adapted to engage with a clamping device for clamping the blocking piece. The lens blank is fixed to the upper surface of the blank contacting element by applying a vacuum within the blocking piece to provide suction through essentially the entire upper surface of the blank contacting element. The disclosure further relates to a method for blocking a lens blank and a use of an element formed of a rigid fluid-permeable material as a part of a blocking piece.

Abstract: A set of eyeglass lens semifinished products is provided and is composed of at least three series of eyeglass lens semifinished products having spherical or rotationally symmetric aspherical front surfaces. The series of eyeglass lens semifinished products differ in pairs in the base material of the series. Each of the series includes at least three types of eyeglass lens semifinished products which differ in pairs and the front surface shapes. The front surface shapes of the at least three types are identical on a central partial surface within the actual surface refractive power range of the front surface of the series in relation to a standard index of refraction of 1.53 between 3.2 D and 6.7 D.

Abstract: A set of eyeglass lens semifinished products is provided and is composed of at least three series of eyeglass lens semifinished products having spherical or rotationally symmetric aspherical front surfaces. The series of eyeglass lens semifinished products differ in pairs in the base material of the series. Each of the series includes at least three types of eyeglass lens semifinished products which differ in pairs and the front surface shapes. The front surface shapes of the at least three types are identical on a central partial surface within the actual surface refractive power range of the front surface of the series in relation to a standard index of refraction of 1.53 between 3.2 D and 6.7 D.

Abstract: A tool for the polishing of an optical surface has a base which has an active surface facing the optical surface. An intermediate layer is arranged on the active surface of the base. A polishing agent carrier is arranged on the elastic intermediate layer. The elastic intermediate layer projects radially beyond the active surface of the base and the polishing agent carrier projects radially beyond the elastic intermediate layer.

Abstract: A tool for the polishing of an optical surface has a base which has an active surface facing the optical surface. An intermediate layer is arranged on the active surface of the base. A polishing agent carrier is arranged on the elastic intermediate layer. The elastic intermediate layer projects radially beyond the active surface of the base and the polishing agent carrier projects radially beyond the elastic intermediate layer.

Abstract: A polishing tool for processing an optical surface of a spectacle lens, having a carrier body and a polishing film, an elastic layer being arranged between said polishing film and said carrier body. Further, there is provision for a surface of said polishing film, which surface is active during processing, to decrease in size in an edge region of said polishing film outwards in said radial direction. Furthermore, an apparatus is provided for polishing an optical surface of a spectacle lens having a polishing tool as described above.

Abstract: A polishing tool for processing an optical surface of a spectacle lens, having a carrier body and a polishing film, an elastic layer being arranged between said polishing film and said carrier body. Further, there is provision for a surface of said polishing film, which surface is active during processing, to decrease in size in an edge region of said polishing film outwards in said radial direction. Furthermore, an apparatus is provided for polishing an optical surface of a spectacle lens having a polishing tool as described above.

Abstract: A thread rolling head with at least two profile rollers provided with a forming thread that are rotatably supported in a supporting unit and a feed motion device that will cause the profile roller to clamp and release a cylindrical work piece, wherein each of the profile rollers constitutes a single piece with its mounting bolts, which make it possible for the profile rollers to be rotatably supported in a supporting unit at one end only.