Ever wonder how your horse's vision differs from yours?
The answer is that your horse sees better in some ways, and worse in others. Because your horse's eyes are positioned farther apart than ours are, he has a much wider field of vision. Unlike school teachers, a horse doesn't have eyes in the back of his head, but it sometimes seems that way. In fact, a horse can see nearly 360? - except for a little blind spot directly behind him and one directly in front.
Most people don't realize that a horse's big nose gets in the way of vision.
Have you ever noticed how a horse stretches out his nose to meet another horse or to check out what you have in your hand? He's not just acting defensively, keeping a distance from you. And he's not "respecting" your space. He's arching his neck and pointing his nose so he can both smell the object and focus on it. Other than that blind spot, though, a horse's close-up vision is excellent.
But his distance vision is a different story. He depends on sound, smell and his excellent memory for shapes and movement to help him make sense of things he sees in the distance. So he can't literally see the halter you're hiding behind your back when you enter the pasture. But he can recognize your characteristic halter-hiding walk.
Because the picture that each eye sees doesn't overlap as much as ours does, his depth perception - the ability to judge distances - isn't as good as ours. So he may get frightened of something that's quite a distance from him.
When a horse sees something unfamiliar, he'll raise his head suddenly, scanning the horizon with nostrils flared and ears turned like satellite dishes trying to catch familiar sounds. We might not say that his vision is good, but with the help of his other senses, his ability to "see" is excellent.
Check out www.vetmedicine.about.com/od/equinehorseanatomy for more information on your horse's anatomy.