Ocelli

Ocelli (singular Ocellus) are simple photo-receptors (light detecting organs). They consist of a single lens and several sensory cells. Unlike compound eyes, ocelli do not form a complex image of the environment but are used to detect movement. Most arthropods possess ocelli. Some species of arthropod do not possess compound eyes and only have ocelli.

A photograph of the head of a solitary bee. Ocelli are visible as shiny bumps on the head of the insect.

Other names for (or types of) Ocelli include:

• Simple eyes

Related terms

• Compound eye
• Facet
• Fovea
• Head
• Ocularium
• Ommatidia

Related groups of terms

• Invertebrate body structure

Related pages on this web site

• Insect body structure

See other words beginning with O