The horse is a prey animal, relying on their senses to assess their environment. Prey species are designed for scanning the environment compared to picking out sharp details. By scanning larger areas, prey is safer from a surprise attack from a predator. Horses use vision to orientate themselves, detect motion and distance, and evaluate the consistency of the environment.
Compared to humans, horses vision has the following characteristics:
- Horses can detect the appearance of objects within an almost fully encompassing circle and are able to identify objects within most but not all of their panoramic field of view.
- The horse may startle when an object passes from the field of vision from one eye to the other eye. For example, you take your dog with on a trail ride. The dog falls behind and jogs to catch up. The horse recognizes the dog on the left but when the dog moves over to the right side the horse jumps unexpectantly.
- Horses are less able to distinguish details and contrast colors
- Horses can see longer distances and can view the horizon and ground at the same time
- Horses are easily blinded by bright light but can see better in dim light
- Horses recognize patterns or outlines. For example, a horse is trail-ridden down a gravel road with no problem. The next time the horse is ridden down the gravel road there are garbage cans out by each drive and the horse spooks at the garbage can. This is most likely due to the garbage can being out of place. It was not there before and now it is a new item to be assessed.
- Horses detect movement quickly. For example, you and a horse are trail riding, when a deer quite a way down the trail runs across the trail. The horse sees the movement of the deer and may react by trying to turn the other direction, or even taking off at a run.
Check out Vision in the Equine for more information on how horses see