Today’s letter O is for Ocelli. Honey bees, and bees in general, have three ocelli in the middle of their head to detect light and movement. These are also referred to as simple eyes because they lack the complex structure of compound or vertebrate eyes. There is no retina and they often have a single lens. So they are not really “simply” though perhaps more simple than other types of eyes.

Overall, bees have five eyes: two large compound eyes like most insects and three simple eyes (ocelli) in the center of their head. The following image is taken from the Bees Wiki and shows both the compound eyes and the ocelli between the antennae.

Honey bees detect light from orange to ultraviolet (UV) wavelengths. They are sensitive to the same sized band of light as humans, just shifted to include UV light. As a result, bees do not differentiate red light from lack of light (black). So if you wear red into the bee yard, the workers will see you as black.

The ocelli help detect the UV patterns in flowers, as well as navigate by the position of the sun in the sky even when it is cloudy.

May you prosper and find honey.