Honeybees have fascinating eyes: all Five of them. Two compound eyes on either side of their head, and 3 “extra” eyes on top. We humans think of two eyes as being “normal”, but for most in the third-largest order of insects, 5 eyes is pretty normal. The two compound eyes can be seen on either side of honeybees’ heads. You must look a lot closer to see the three small eyes, the ocelli, that lie between their antennae’s on the top of their head.
We can all see the large compound eyes on bees, especially on drones (males). Each of these compound eyes has 6,900 tiny lenses called facets. Each of these tiny lenses has its own photosensitive cells. The facets are in groups, each with a special skill: patterns, polarized light, colors and motion. The images from the thousands of lenses join together in the honeybee’s brain. Bees have excellent detection of color, polarized light and motion. But seeing outlines and forms is not a strong point. The resulting image from all those facets in their compound eyes is believed to be like a mosaic. Bees’ color perception is different from ours. They can see into the ultraviolet range, but to them, red is black.
Honeybees apparently can detect a motion that happens in 1/300th of a second. If a movement takes 1/300th of a second, a bee can see the beginning and end of that movement. We humans would never see it. For us to register motion a movement must take longer than 1/50th of a second. A field of flowers or the blossoms of a tree may look still to us, but to the bees, those flowers are moving.
We cannot see polarized light, although many insects can. This ability allows them to “see” the sun on cloudy, overcast days. The ability to see polarized light helps the bees navigate.
Also assisting in navigation are tiny, sensitive hairs which grow where ever the facets meet. These hairs are believed to detect wind direction, and allow the bees to stay on course in windy conditions. When these hairs were removed from bees ina 1965 experiment, the bees could no longer find their feeding sites.
Honey bee navigation is further assisted by the three “simple” eyes located in a triangular pattern between the honeybees’ antennae. “Simple” here is not just a description, it is a technical term. Simple eyes are also called ocelli (occellus is Latin for “little eye” according to Wikipedia). Each eye has only one lens. Their only purpose- but a vitally important one- is to allow the bees to use sunlight for navigation.