What is a "compound eye"?

A compound eye is a specialized visual organ found in many arthropods, particularly insects and crustaceans. It consists of numerous tiny individual visual units called ommatidia, each with its own lens, photoreceptor cells, and nerve fibers. These ommatidia work together to form a mosaic-like structure, allowing the compound eye to perceive a wide field of view and detect motion effectively. Unlike the single-lens eyes of vertebrates, compound eyes provide insects with a highly sensitive and rapid visual system, enabling them to quickly respond to their environment, detect predators, navigate, and locate food sources. The compound eye's ability to detect rapid changes in light and movement is well-suited for the active and agile lifestyle of many arthropods.