Proclear are the world's first soft monthly contact lenses containing "phosphorylcholine", a natural substance. It is used in medicine (artificial arteries, etc.) because of its absolute tissue compatibility. Proclear contact lenses are considered by the eye to be the body's own substance. The lenses remain evenly moist throughout the day until late at night and there is practically no feeling of dryness in the eye. Proclear are particularly suitable for screen work. Due to its electrical neutrality, the surface of the Proclear contact lens does not tend to form deposits, e.g. lipids and proteins from the tear film.