The optical elements of ZEISS lenses feature T*® anti-reflective coating on all surfaces and an optical design that guarantees images of superior brilliance at all times, even in unfavourable lighting conditions. We apply the anti-reflective coating to the lens surfaces by the vapour deposition of extremely thin, transparent layers on the glass. In this process, special substances are vaporized with extremely high energy in a high-vacuum environment and are subsequently deposited on the glass surfaces, one after another, as layers with precisely controlled thicknesses to achieve the desired reduction of reflective properties. The first coating techniques were employed by ZEISS as long ago as in the 1930s.