Photochromatic or photochromic technology has been in force since 1940. The first to succeed in introducing photochromatic lenses to market was PhotoGray, in 1962. Thereafter, intense competition began in the field among various players. Different techniques are used in the photochromatic or photochromic lens manufacturing process.
Corning Ophthalmic was the first to start experimenting in the field and they used in-mass technology for the production process. In this method, photochromatic materials are mixed with the lens material to have even distribution of photochemical compounds. Due to the large number of photochromic molecules distributed uniformly, the effect never wears out. This technology, however, results in uneven colour as thickness of glass increases.
In the next method, photochromic cells are embedded throughout the material resin. When the surface of the lens is subjected to wear, new photochromatic cells get activated to replace the old one. This provides the user, long-lasting and reliable performance. Augen Optics uses this technology.
Digital lens casting system technology is used for production of gray and brown glasses. In ChangeRx photochromic lens manufacturing, organic photochromatic molecules are mixed and blended with plastic lens monomer.
In imbibition and Trans-Bonding technology, photochromatic compounds are driven into hard resin lens surface. The molecules permanently gets embedded into the lens. This technology is used with lens materials like polycarbonate.
In, BWS (Behind the WindShield) technology, the glass reacts only to visible light rather than UV. In Confined Tint technology, the photochromic or photochromatic compounds are placed in the front surface of the semi-finished lens.