The beholder of the eye...

From Jim: Proportionately, horses have the largest eyes of any land animal. We often look at and and into their beautiful eyes because it's so pleasing to do. Their eyes are way different than ours in form and function. If you wanted to look through their eyes, you couldn't do it because they see differently than we do and your brain wouldn't have the receptors to use the visual information. They can see monocularly and independently with each eye at the same time. You can't do that. Moreover, they can readily transition to binocular vision, fuse the images, and enjoy good depth perception. The retina of their eye has proportionately more rods to cones. They percieve motion and acquire light better than we do. Better night vision. Better motion detection. You'd think something was trying to eat them. Their color vision lacks the red spectrum. They percieve shades of blues and greens and, of course, black and white. They see better in the dark, but are easily night blinded by brilliant transitions. That's something to consider when riding in low light conditions. Bright oncoming headlights leave them temporarily blinded. Their peripheral vision is exceptional, around 270 degrees, and very sensitive to motion. They have blind spots fore and aft. The frontal blind spot extends to around four feet in front of their nose. If your standing there, they can't see you. They can't see their nose. To the rear, the hooks of their hips are about the limit. Walk up quietly behind them at your peril. They can't see their feet, or yours, for that matter. Although vision is an important sensory input for horses, their other senses are even keener. A horse tends toward nearsightedness and their acuity is not very sharp, maybe 20/40 or so. One eyed horses seem to do very well. And, depending on their ability to adjust, horses that lose all vision can function satisfactorly. There are behavioral issues linked to a horse's visual equipment that the horseperson should take into account for the animal's sake and the human's safety. As one integrates their knowledge about the organic behavioral nature of equines, the role vision plays shouldn't be over or underestimated. It's just one more aspect of getting to know horses, donkeys and mules! And, of course, there are those profound moments when our eyes meet theirs and the differences between our species are left behind for a moment.