Eyes Equine eyes have played a key role in the long-term survival of the horse. Keen vision is the horse's primary asset as he seeks to avoid a panoply of dangers, ranging from predators to prairie-dog holes. His distance vision is superior to human vision; his peripheral vision covers a remarkable radius of about 340 degrees, allowing him to see almost back to his tail on both sides.
The area's around #1 shows where a horse has monocular vision. The area around #2 shows where a horse has binocular vision.
The horse has one of the biggest eyes of any land animal.
Some information about horse vision:
- There is a blind spot directly behind the horse's hindquarters.
- The horse can't see directly below its head.
- The horse has to lower its head to see faraway objects.
- The horse has to raise its head to see close objects.
- If an object is closer than a few feet, the horse can't see it with its binocular vision.
- It takes time for a horse to adjust its eyesight going from a dark area to a light area or vice versa.
- The horse needs to use binocular vision for depth perception and distances.
- The horse vacillates between use of monocular and binocular vision.
Horses, with their eyes being located on opposites sides of their head, are mostly "monocular". Their "binocular" vision is limited to an area in front of them, in a line down their nose.
Monocular vision is used to view separate things with each eye at the same time, to the side and rear of the horse. Binocular vision is frontal vision, using both eyes to look at an object.
Horses have a blind spot behind them and directly in front of them. As they move forward, they are unable to see within a few feet. It is felt that they "memorize" as they go forward, to know where to place their feet. The horse cannot see approximately two to four feet in front of its face due to the placement of the eyes on the head. Therefore, the horse cannot see the food it eats.
To judge distances, a horse uses its binocular vision. The horse must have use of his head to be able to use his vision to his best advantage.
From a site about horse vision: "So if a horse needs to look down his nose to see where he is going, what happens when he is 'on the bit' as in showing or dressage? A horse who is flexed at the poll will have his head vertical (at right angles) to the ground and cannot see straight in front of him, only down his nose towards the ground.
Recent research found this blind spot in front of the horse is about the width of his body and a horse 'on the bit' must rely on the rider for direction as he is almost working blind!"
