glossary

A condition, usually characterised by raised pressure in the eye which causes damage to the optic nerve resulting in defects in the field of vision. It is treated by reducing the pressure in the eye. Increase in intra-ocular pressure resulting, if left untreated, in an irreversible deterioration of the optical nerve and of the retina, as well as an alteration of the visual field, i.e. a reduction in visual performance, often accompanied by headaches and aching eyes. A disease of the eye characterized by increased intraocular pressure. A common cause of preventable vision loss. May be treated by prescription drugs or surgery.

Glaucoma in which the intraocular pressure is normal but there is progressive optic nerve damage and visual field loss. Also known as Low Tension Glaucoma.

A type of vision test in which progressively dimmer lights are moved from the peripheral vision into the central vision, using an instrument that allows the point at which the light is first seen to be accurately mapped. In this test, a trained perimetrist moves the stimulus; stimulus brightness is held constant. The limits of the visual field are mapped to lights of different sizes and brightness. Also known as Goldmann kinetic perimetry.