Ocelli

Definition

Simple eyes found in many invertebrates, including insects and arachnids, that typically have a single lens and are used to detect light intensity and movement.

Etymology

From Latin 'ocellus', a diminutive of 'oculus', meaning 'eye'.

Example

The ocelli of a dragonfly help it detect changes in light intensity, which assists in stabilization during flight.

Synonyms

• Simple eyes

Related Terms

• Compound eyes
• Photoreception
• Invertebrates
• Vision

Usage Notes

Ocelli are distinct from compound eyes and are usually found in sets of three on the heads of adult insects.