compound eye(s) - the two large many-faceted eyes placed on each side of the head of insects, besides which they may also possess simple eyes (
ocelli). Compound eyes consist of numerous hexagonal facets, the lenses of which combine the characters of both crystalline and vitreous humours. The individual visual elements are called
ommatidia (singular
ommatidium). Compound eyes are sometimes called
oculi (singular
oculus), or simply,
eyes. The compound eyes are particularly prominent in certain
Diptera (flies) and
Odonata (dragonflies and damselflies).
