Academic Decathlon Science Practice Test

Compound eyes are made up of many small visual units called ommatidia, each with its own lens and photoreceptor cells. This mosaic arrangement lets each facet point in a slightly different direction, producing a very wide field of view and excellent sensitivity to movement. The defining feature is the presence of numerous ommatidia that collectively cover a broad visual area.

This differs from a simple eye, which has only a single lens, and the eyes aren’t located on the antennae. Insects can perceive colors through multiple wavelengths, but the key characteristic is the many ommatidia contributing to a wide field of view.