I volunteer with a group helping kids with simple science concepts, and I was wondering if it has been sorted out whether horses can see in color? This question comes up over and over.

Back in Pony Club, we were taught the traditional view that horses see in black and white. Then, somewhere along the line I read that there was some debate about that. Other than what we all have experienced that would suggest some horses are able to tell color, how do you know for sure what they really see?

The current evidence indicates that horses do, in fact, experience color vision. It is not the same type of color vision we humans perceive. In humans and other primates, color vision is called trichromatic, meaning color vision is based on the ability to detect red, green, and blue wavelengths and their combinations. In other mammals studied, mostly the farm animal species and birds, evidence supports dichromatic color vision, meaning these animals have the apparatus and ability to detect only two of those three colors in the spectrum and their combinations.

For horses it is currently believed that their dichromatic color vision includes the ability to perceive green and blue, and probably their color vision is somewhat similar to what is known commonly in people as red-green color blindness (or more correctly called color deficiency). This means that certain colors, especially red and related colors, appear more green.

How Do You Know?

Scientific evidence of color vision in animals has come from research of several types, including anatomy, physiology, and behavior. Those folks who study the basic anatomy