glossary

Corrects eyesight disorders and is a combination of material, optical surface and coatings.

Sightless area within the visual field of a normal eye, where the optic disc attaches the optic nerve to the eye. Caused by absence of light sensitive photoreceptors where the optic nerve enters the eye.

Opacification of the crystalline lens. An extraction of the lens is usually replaced by an intra-ocular lens (implant). Clouding of the crystalline lens, which may prevent a clear image from forming on the retina. If visual loss becomes significant, surgical removal is required. Types of cataracts include traumatic, congenital and age-related. .