Roger Powell, a ranger and historian at Ford's said that a horse blind in one eye was not that uncommon during the 1800s. Any of us that have had to go out in a field and try to get a horse that lets you get within a few feet, then takes off know the frustration. An owner would sometimes put out an eye so they could approach a horse on that side without being seen. My daughter cares for a number of horses and one is blind in one eye, and it is a very frisky animal, difficult to manage. Approaching from the blind side works.