Understanding How Horses See

It's easy to think that horses and other animals perceive things exactly like we do. There's no way to know exactly how horses see because we can't see the world with a horse's eyes and brain, but by studying the individual components of the horse's eye, scientists can gain an understanding of what it is capable of. The structure and position of their eyes are somewhat different than humans', which makes a difference in the distance, color, vividness, and visual field a horse experiences.

Color Perception

Many people think that animals, including horses, are colorblind and only see in shades of gray. This is not true. Horses do see color, but they may not see it as vividly as we do. This is because they can only see two of the three visible wavelengths in the light spectrum, which is somewhat similar to the way colorblind humans see. 

Your horse doesn't see the color red, but it can see blues and greens, so the red apple or the bright orange carrot you offer as a treat may actually appear brownish or greenish to your horse.

Night Vision

If you've ever called your horses in from a pasture in the dark, you'll no doubt have been surprised as they barreled towards you at a wild gallop, but arrived without stumbling over rough ground. They may not see color as well as we do, but they see much better in the dark than we can because their eyeballs have more of the structures that pick up light. If you've taken a picture of a horse with a camera flash, you may see that the horse has ghostly white eyes. This is caused by the tapetum lucidum, a membrane at the back of the eye that reflects light and also aids their night vision.