glossary

An ophthalmic lens that incorporates three lenses of different powers. The main portion is usually focused for distance (20 ft.), the center segment for about 2 ft., and the lower segment for near (40 cm, or 16 inches).

A form of color blindness exhibiting loss of the blue receptor, inherited in an autosomal recessive fashion.

Inflammation involving the pigmented layers of the eye (the iris, ciliary body and choroid).