median eyes

Definition

Simple eyes located in the central part of the head in many arthropods, particularly spiders and some insects, used primarily for detecting light intensity and movement.

Etymology

From Latin 'medius', meaning 'middle' or 'central', and 'oculus', meaning 'eye'.

Example

The jumping spider uses its median eyes to detect motion and gauge distances when hunting prey.

Synonyms

• ocelli

Related Terms

• ocelli
• lateral eyes
• compound eyes
• spiders
• insects

Usage Notes

Median eyes do not provide detailed images like compound eyes but are effective in sensing changes in light and detecting movement.