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The first contact lenses were made of glass, in 1888. Initially the glass was blown but soon lenses were made by being ground to shape. For the first fifty years, glass was the only material used. The lenses were thin, yet reports of injury were rare. In 1938 perspex (polymethylmethacrylate, or PMMA) began to replace glass in contact lens ...
This can be done, for example, with ring tools. Next, the lens surface is polished to its final form. Typically this is done by lapping—rotating and rubbing the rough lens surface against a tool with the desired surface shape, with a mixture of abrasives and fluid in between. Typically a carved pitch tool is used to polish the surface of a lens.
Leica 50 mm f /2.0 Summicron-R 2nd version – 1977 (built-in lens hood, 3-cam and R-cam only version) Leica 50 mm f /1.4 Summilux-R 1st version; Leica 50 mm f /1.4 Summilux-R 2nd version; Leica 50 mm f /1.4 Summilux-R 3rd version – 1997 (ROM contacts) Leica 60 mm Macro-Elmarit-R 1st version – 1972 – outside bayonet lens hood fitting
Optical lens design is the process of designing a lens to meet a set of performance requirements and constraints, including cost and manufacturing limitations. Parameters include surface profile types (spherical, aspheric, holographic, diffractive, etc.), as well as radius of curvature, distance to the next surface, material type and optionally tilt and decenter.
A bayonet mount A bayonet mount before and after insertion Early-19th century socket bayonet Socket of a bayonet. A bayonet mount (mainly as a method of mechanical attachment, such as fitting a lens to a camera using a matching lens mount) or bayonet connector (for electrical use) is a fastening mechanism consisting of a cylindrical male side with one or more radial pegs, and a female receptor ...