What a Bee Sees

What does the world look like to a bee? Although we can’t see through a bee’s eyes ourselves, we are closer to solving the mystery thanks to science. Nobel Prize winner Dr. Karl von Frisch pioneered the first research into bee vision. In one of his experiments, sugar water was placed over blue squares and plain water over grey ones. Eventually, Frisch was able to train bees to go to the blue square, without using sugar water, and in 1914 reported that bees could see color.

Today we know a lot more about things bees can see that humans cannot. Unlike us, bees can see ultraviolet light (UV). Flowers use this to their advantage to attract bees. They create patterns that direct bees to the pollen of the flower. These patterns make finding nectar and pollen much easier for the bee.

Bees are able to see this UV light because of the unique structure of their vision system. Three small eyes on top of a bee’s head each have a single lens and help the bee maintain stability and navigate. They also allow the bee to gauge light intensity and see UV light.

Diagram showing compound eyes and ocelli

Humans and bees are both trichromatic which means that we have photoreceptors within our eyes that have three base colors for our brains to work with. The three belonging to humans are red, green, and blue whereas the three belonging to bees are ultraviolet, green, and blue. This is also why bees cannot see the color red.

Bee color vision compared to human color vision

The eyes we are used to seeing are the two compound eyes on the sides of a bee’s head. These eyes give bees a near 360-degree view of the world. Comprised of many curved microscopic lenses, compound eyes put together images taken from each lens to achieve a wide view without the bee having to move its head. Each lens, or ommatidium, focuses light and can detect color.

An advantage of this system is that bees do not have to turn their heads to see their environment and do not have blind spots. However, bees can’t focus on objects by changing the shape or position of their eye so they must move closer or farther away to see things clearly. Scientist and artist Andy Giger created a Bee-Eye simulation that gives us a sense of what this is like.

Flying helps a bee see better due to this compound structure and also because bees have a high flicker threshold which allows them to see individual flowers while traveling fast.

Compare this to a human’s vision while driving down the highway. Looking out the window at flowers by the roadside, a person is likely to see only a blur of color. Bees actually respond better to moving objects. This is why they have no trouble pollinating moving flowers.

WARNING: This video contains flashing lights.

Flicker Frequency Test

In this video a light flashes to demonstrate flicker frequency. Towards the end the flashing speeds up so fast that a human is no longer able to recognize it as flashing anymore. Bees have a much higher threshold and would be able to still see the light flickering.

So, bees can’t see the color red and they can’t focus in on objects, but they can see UV light, distinguish individual flowers while travelling at speed, and view the world in panoramic mode all the time. While this wouldn’t be practical for a human, it is essential to the function of a bee.