Most optical illusions tend to work only on humans, whereas animals shrug them off and see the real world. There is one effect that works on humans and animals both. It shapes how many animals see colors – even if they see completely different colors than we do.
The Bezold-Brucke Effect is a well-established optical phenomenon. It tells us that we can't see color as well as we think we can – or that colors aren't as straightforward as we think they are. If you are looking at a light source, nearly any light source, you'll notice it has a distinctive color. As the light source brightens, that color will change to something either more blue or more yellow, depending on the source of the light. (Which way it goes will depend on the source. High frequency light will turn bluer. Low frequency light will turn more yellow.) If the light source dims, the color will shift toward the red or green regions of the spectrum.
So what? Our eyes are tricked in so many ways that it's sometimes a surprise that we see anything correctly. It seems, though, that this is an effect that's shared by a lot of different animals. By training bees to go to light sources, and altering the intensity of those light sources, researchers have found that bees perceive a Bezold-Brucke Effect, too. Bees, unlike humans, have the ability to see ultraviolet light. It's one of the ways they pick out certain flowers. Despite seeing entirely different colors than we do, they're taken in by the same illusion. Although humans and bees see completely different worlds, both worlds share the same weakness.
Usually, we humans are isolated in our mind-eye deficiencies. We have to accept our sensory deficits when it comes to other species. At last we have an optical illusion that we share with the rest of the animals.
Image: Thomas Tolkien