Abstract

Contact lenses are worn in contact with the eye. Corneal lenses cover the greater part of the cornea, scleral (haptic) lenses cover the whole of the front of the eye and lenses of intermediate size cover a little more than the cornea. Originally contact lenses were made of glass, but now most are made of plastics, usually polymethyl methacrylate Perspex. More recently, soft plastics (hydrophilic lenses) have been used with some success.