From the word light alone, we can see that it means "bright" and "transparent". Optical lenses must have these attributes and have good transparency.
Optical lenses are highly transparent, chemically and physically homogeneous. Optical lenses have specific and precise optical constants. Optical lenses can be divided into silicate, borate, phosphate, fluoride and chalcogenide series. Optical lenses have stable optical properties and high optical uniformity. Optical lenses have selective absorption and transmission properties for specific wavelength in ultraviolet, visible and infrared regions. According to the spectral characteristics, it can be divided into three types: selective absorption type, cut-off type and neutral ash type.
Optical lenses are indispensable optical materials for the manufacture of lenses for advanced cameras and periscopes. The raw materials of optical lenses are oxides, hydroxides, nitrates and carbonates. According to the requirements of formulation, phosphate or fluoride are introduced into optical lenses. The difference between optical lenses and other lenses is that as an integral part of the optical system, it must meet the requirements of optical imaging.
Compared with glass, optical lenses made of organic materials have lower hardness and are easier to scratch. The scratches of optical lenses produced by larger gravel are deep and rough around. Optical lenses are then observed with a microscope and compared with the wear of the lenses. If the optical lenses are located in the central area, the visual acuity will be affected. The hardness of the base of optical lens and the hardness of the antireflective film are quite different. The new theory holds that a layer of anti-wear film is needed between the two, so that the lens can act as a buffer when subjected to grit friction, and it is not easy to produce scratches.