Your horse’s eyes aren’t just there to help him find food, but he relies on his sight to keep him and the others in the herd safe and to help move around his environment.
How your horse sees
Your horse has the largest eyes of all land mammals and can see almost 360 degrees around him as his eyes are set wide on his head. His rear view vision is restricted as it is from his shoulder forward, so he naturally wants to flee away from things behind him, or turn so he can see them better. But as a prey animal this ability to see things sneaking up on him was key to his ancestors’ survival in the wild. Raising his head helps him focus on suspicious objects in the distance and gives him better depth perception. He will lower his head to see closer objects.
Your horse sees most things with one eye (monocular vision) rather than both simultaneously (binocular vision). He only uses binocular vision for a small area in front of his head. This is why he’ll spook at something he’s walked past on the other rein and reacted to already. He’s seeing it for the first time – with his other eye.
There’s a blind spot just in front of his nose and also behind his head, so when you’re mounted if you can’t see either of his eyes, then he can’t see you.
* The way to tell if your horse is using one or both eyes is to watch his ears. If he’s trying to focus with both, he’ll prick both ears straight out.
* Sensory hairs around your horse’s eyes trigger the blink reflex if he gets too close to hedges or other eye-damaging surfaces while grazing and drinking.
Help him focus when being ridden
When he’s jumping a fence, your horse will raise his head on the approach so he can get a better idea on the height and depth of the jump. Then as he gets closer he’ll lower it so he can see the fence close-up and gather himself for take-off. If you restrict him performing this action, he may become stronger, run out or stop because he can’t see well enough to make it work.
A horse working in a contact with his head flexed at the poll and vertical won’t be able to see straight in front of him, only down his nose to the ground. So he’s relying on you for direction through the aids.