California Riding Magazine • November, 2012

Success Through Science
Understanding your horse's vision is a terrific training aid.

by Andrea Kutsch

Vision is one of the horse's most important survival mechanisms. It supports the horse's brain with immediate information that influences their actions and reactions and behavior. You can use this information in practical work and training of your horse.

The horse's vision is designed to give a wide panoramic view of the surroundings, riding arena, stable, trailers or wherever you want to bring them to. In essence, the horse has a 350-degree range of vision. This characteristic enabled horses to thrive in the wild, but it complicates things in a domesticated environment because this field of vision includes several blind spots. Blind spots are areas they can't see when their head is straight, so they have to turn their head around to make sure that there are no predators in that area.

This greatly influences their movements. It can influence them, in schooling or competition, to refuse the rein to get their neck free to see and check their surroundings by themselves. Or it can influence them to refuse at a jump because of an unfamiliar flowerpot nearby.

Because the eyes are set wide apart on each side of the head, most of the horse's field of vision is seen with one eye, which is called "monocular" vision. You and I have both eyes in the front of our head, so we see most things with both eyes. This is called "binocular" vision and it provides quite a different view.

Only when both eyes, taking turns, are able to look at an object, can the horse really "think" and work out what the object might be. That's when they can decide if it might be something they should fear and run away from or if it might be something they can accept and stay with. In fact, only when both eyes are looking at, let's say a jump, does the horse have binocular vision.

As you can see on the illustration, the binocular vision (both eyes able to focus on the object) is only an angle of 60-70 degrees in front of the head. This is the only angle in which the horse can achieve depth perception.

Through movement of its head, the horse can focus on an object with both eyes. This allows the horse to view the ground in front of them with both eyes and deal with the information in his whole brain. There are more issues that are responsible for misinterpretations of a horse's behavior in many situations, but for this column we'll stay with binocular and monocular vision and how you can use this understanding in training.

Away We Go

Let's say your horse is perfectly fine at home, listening to you and is focused on your signals of legs and hands and you have trained him well. Now you are traveling to a dressage competition and your horse is shying while riding into the ring. Most of the time, it is only jumping aside because he is not able to check out with both eyes what this object might be: a predator or just the judge's head. The horse will talk to you with his body language in this situation. It will tell you immediately with little signs that it feels very unsure about this one thing over there and will give you a warning because you are his most important, trusted partner in this moment.

The warning can be read when you are aware of what your horse is telling you. Please keep in mind that your horse never wants to interact against you just to be terrible – there is always a survival reason in his message. Let's say the message is either shying or working against your rein and the bit to move the head toward the directions his eye needs to assess this object.

The equine eye is among the largest, in terms of absolute dimensions, of any terrestrial mammal. The horse relies heavily on visual information about its environment. With his large retina and a relative image magnification that is 50 percent greater than that of your own eye, the horse's eye allows visualization of a wide panorama of the horizon and also the area ahead where feet will be placed and fodder will be selected. They need head movement to enable their binocular vision in such situations. Horses also use monocular depth cues to judge distance.

Use the minute when riding into the competition to read your horse's every movement to figure out if there is something around he can not see or can not understand. You need to have his full cooperation and focus on you to win in a competition – whether it is jumping or dressage or pleasure riding in the woods or country or at the beach.

Lions In The Trees

When the horse refuses one of your signals, like a leg aid, and he stops being focused on an obstacle, keep in mind what you can do in this moment to help him to see and get the information he needs. Give him a chance to see for himself that the dog up ahead is, in fact, only a dog and not a lion in a tree.

When the horse wants to lift its head, the binocular area of vision is directed at the horizon. Allow him to lift his head for a second and then work in arcs instead of straight lines to enable his monocular vision (right eye and then left eye) for scanning and depth perception.

In this position monocular lateral vision is compromised. However, when the head is lowered and the binocular vision is directed at the area directly in front of his head, the lateral monocular fields afford good lateral horizon vision. Effective use of the binocular field is required when a horse attempts to discern an object that is close and low. The horse is best able to use its binocular field of view by arching the neck and rotating the head. It can focus on the object by simultaneous rotation of the eye downward to optimize orientation of the visual streak. (Source: Harman AM, Moore S. Hoskins R, Keller P. Horse vision and the explanation of visual behavior. Equine Veterinary Journal. 1999; 31 (5): 384-390).

Younger horses, by the way, tend to carry the head higher and therefore may not notice stimuli or objects as readily as older horses, especially those that have been trained not to carry their neck straight and head high. A study showed that horses were able to discern stimuli better in overcast weather than in sunny conditions. (Source: Saslow CA. Factors affecting stimulus visibility for horses. Applied Animal Behavior Science 1999; 61:273-284).

In one of my own studies, 32 horses were ridden towards a scary object – first on a straight line, then in curves. Their behavior reinforced my hypothesis that a horse would approach an unknown object while riding in curves rather than on a straight line. A significantly lower level of stress could be observed among the horses led in curves. They left a smaller amount of droppings, they breathed more calmly, they focused on the object less intensely with their ears and they showed weaker flight reactions. No adrenalin or stress hormones are shown which means that the horse can continue learning instead of producing fear and trying to escape from the situation.

Andrea Kutsch founded the Andrea Kutsch Academy in her native Germany in 2003 and is now introducing her teaching and training techniques to the United States. Her next Southern California appearance will be a Nov. 18 seminar at the Del Mar Horsepark. For more information and complete local appearance dates, visit www.andreakutschacademy.com.