Polaroid (polarizer) Polaroid (polarizer) Polaroid is a type of synthetic plastic sheet which is used as a polarizer or polarizing filter. A trademark of the Polaroid Corporation, the term has since entered common use. The original material, patented in 1929 and further developed in 1932 by Edwin H. Land, consists of many microscopic crystals of iodoquinine sulphate (herapathite) embedded in a transparent nitrocellulose polymer film. The needle-like crystals are aligned during manufacture of the film by stretching or by applying electric or magnetic fields. With the crystals aligned, the sheet is dichroic: it tends to absorb light which is polarized parallel to
Polaroid Eyewear history Polaroid produced polarized sheets to be used for the elimination of automobile headlight glare. For the same reason sunglasses and filters were use by the American Army, especially for aviation, indeed Polaroid glasses were thought to protect aviator from sun light but also atomic bomb explosions.Cool-Ray was a division of American Optical for the sunglasses. It was the originator of the polarized sunglass as it is known today. It manufactured the lenses using a process that was licensed from Polaroid Corporation. Cool-Ray paid Polaroid a royalty in the early 1940s. In 1965 Polaroid moved its production in Vale of