Horses vision compared to humans
It’s easy to think that horses and other animals perceive things exactly as we do. But that’s actually very far from the truth, in fact, 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.
Many people think that animals, including horses, are colorblind and only see in shades of gray. In reality, 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.
However, 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 a membrane at the back of their eye that reflects light and also aids their night vision, called tapetumlucidum.
Furthermore, the protective layer in the corner of a horse’s eye, called the nictitating membrane, helps prevent irritation from dust and objects like grass seeds and stems. You’ll often see a bit of tearing and grime in this area that can be wiped away with a soft damp sponge or cloth as part of your grooming routine.