glossary

A common type of color vision test that can help determine general and specific inherited color vision deficits. It consists of a series of color plates in which the test taker is asked to identify numbers or geometric shapes composed of specific colors that are hidden within a field of spots of very similar colors. People with normal color vision can see the numbers or geometric figures while people with abnormal color vision cannot. See Ishihara Test Ishihara

A line connecting a series of points in a visual field at which a person is able to detect a certain size and intensity of light. Isopters in normal visual fields are oval in shape.

A disease entity that most commonly affects young men in their teens and early twenties and causes significantly decreased central vision in both eyes. The genes that cause LHON are carried on small circular mitochondrial DNA molecules that are inherited from an individuals mother. This condition is extremely rare (affecting fewer than 1 per million people per year) and does not affect everyone who harbors the genetic defect. The visual field defects in LHON are typically cecocentral scotomas. There are three other eye diseases named after Theodore Leber: 1) Leber congenital amaurosis (blindness at birth) inherited in an autosomal recessive fashion, 2) Leber’s stellate neuroretinopathy (a non-heritable condition associated with cat scratch disease) and 3) Leber’s military aneurysms (a non-heritable vascular malformation of the retina similar to Coat’s disease).