are connected to cells that send information about motion on a fast track to the brain. This combination gives horses an extraordinary ability to notice tiny rapid movements. If we had a horse’s rods, we’d shy all the time at the countless zips of motion flying through our view. Riders often complain that their horses are “shying at nothing”—in fact, they are shying at very real sights that we have too few rods to sense. What’s truly remarkable is that horses don’t shy more and that they allow us to modify the behavior at all.
So, rods and cones transmit a scene’s pattern of light and dark to the brain. The human brain then takes half a second to process each glance at the world and determine what it has seen—shape, color, size, distance, meaning, importance, and so on. Half a second of processing is out of the question for a horse in the wild: He needs to notice the faintest wave of the grasses and step on the gas. If the movement turns out to be a bicycle instead of a lion, that’s okay. Little is lost by running from a bicycle.
By nature, the horse relies on peripheral motion vision for safety. It dictates his need to startle or bolt—and otherwise “misbehave”—while ridden. Help him out by sharpening your own peripheral senses. Try to become more aware of objects behind and to the sides of your eye, putting your ears, nose, and knowledge to work. Begin to notice with your body where your horse is looking—it’s an intuitive skill that develops with attention and practice. If horses are all jacked up in an area where they’re normally calm, investigate. Chances are good that they notice something you do not and are trying to tell you about it.
Blind Spots
Despite its horizontal band of panoramic vision, equine eyesight includes a number of blind spots. Without changing position, the horse cannot see above his neck or back, beneath his belly or neck, or directly behind him. The sharp acuity needed to inspect or identify objects is best in a horizontal streak at the horse’s eye level, due to the distribution of rods and cones in the eye. So nearby dogs or children on the ground, or balloons and birds above eye level, are hard for the horse to spot until they move.
The area to the outer sides of the horse’s back legs is only barely seen. Surprised from behind, even the sweetest horse can kick in any direction, causing severe harm or death. That’s why we approach a horse’s hindquarters from the shoulder, moving back while speaking, standing close, and touching his side. Lesson number one to new riders is never to walk up behind a horse.
Another blind spot exists in front of the horse’s face, from eye level to the ground below his nose and out to about six feet. A hand suddenly raised in this area appears to come from nowhere. Horses cannot see the grass they eat, the bit they accept, the fingers that stroke their muzzles, or the ill-supervised child who stretches up to kiss their soft noses. Instead, they use their long mouth whiskers to sense this area. A horse whose whiskers are shaved is at a sensory disadvantage.
Finally, there’s a blind spot inside the equine eye that projects onto the visual scene when horses move. All those cells at the back of the eye transmit their signals along the optic nerve to the brain. To carry them, the optic nerve has to connect to each eye, and where it connects, rods and cones cannot exist. This location is called the optic disk (fig. 3.5). It occludes sensory receptors just like a manhole cover hides the drain below a street.
3.5 The optic nerve creates an internal blind spot where it exits the human and equine eye. Cells at the optic disk cannot sense visual information from that part of a scene.
When the head and eyes remain still, the visual area of the world that corresponds to the optic disk becomes invisible. This is true for people and horses—although the equine optic disk and its corresponding blind spot are larger than ours. In daily life, we move our heads and eyes around to solve this problem. Human brains also fill in the blind spot by imagining objects that must be there even though our eyes can’t see them.
If you find the blind spot in your eye, it will be easier to understand the blind spot in your horse’s eye. Take a look at figure 3.6. Hold the book up so that the cross is in front of your left eye. Close your right eye and stare at the cross with your left eye. Without moving your left eye, begin to notice the outer periphery of your vision so that the black circle is visible. Now move the book in and out slowly—closer and farther from you. When the book is 4 to 12 inches from your left eye, the circle will disappear. That’s your blind spot! When you find it, make tiny movements with the book so the circle falls into and out of the blind spot. It will vanish then reappear.
3.6 Find your blind spot. (Please see text for instructions.)
You can play games with your blind spot. Don’t tell anybody, but in boring academic meetings, I used to focus my eye just to the side of where a trying colleague was seated. Then with imperceptible movements, it was possible to move the person’s face into and out of my blind spot for some private entertainment. You can learn to do the same. Stand far enough back at a horse show, and you can even make a naughty pony disappear.
More importantly for our purposes, your horse has a roaming blind spot large enough that an object can disappear at the right distance. This object could be a bird, dog, or small child, for example. If we step silently out of a horse’s blind spot, or even if we remain stationary but the horse moves, we might startle him. Sudden discoveries make horses nervous—no prey animal wants predators popping in and out of sight, or demanding frontal views and preventing escape, all while the brain says, “Run!”
Groundwork
Most trainers use groundwork when starting young horses under saddle. Groundwork refers to any form of training in which the horse is not being ridden. We use it to teach leading, longeing, ground manners, and respect for human space. But we often forget that it’s useful in adult years as well, to teach a horse to back, spin, jump, or move laterally, for example. And it’s an excellent technique to revert to when problems arise.
The key is to realize that it’s a lot harder for horses to relax and learn while we’re sitting on them. So, step off and give them a better chance. Don’t worry, you’ll get back on again before the lesson is over. Remain quiet and calm, moving the horse with your eyes, hands, body position, voice, lead, reins, and/or a whip used only as an extension of your arm to touch the horse’s hindquarters. Groundwork does not require chasing a frightened horse in tight circles with flapping plastic bags tied to a stick. This is more properly called “frightwork,” in my opinion, and it usually causes more harm than good. Good groundwork takes skill and practice. Take the time to learn it well, and it will help your team.
Chapter Four
Training with Vision
We’ve seen that equine acuity and focus are poor, but peripheral range and motion detection are excellent. Let’s round out our understanding with a few added aspects of equine eyesight: night vision, depth perception, visual capture, and color vision.
By nature, equestrians ride on the basis of human assumptions, imagining—if we ponder it at all—that the horse visualizes depth and color the same way we do. We also assume that other equine senses are subordinate to vision, as ours are. Because of misinformation concerning night vision and our own inexperience with it, we presume that horses see details in the dark with superhero sensitivity. The reality is quite different. Doubling down on these discrepancies between human and equine sight explains many common problems within the horse-and-human team.
Night Vision
Horses can see in the dark, right? So they have no trouble jumping at dusk or loading onto the trailer before dawn? Well, not so
