If you look at the evolutionary anatomy of eyes, you'll notice some major differences between humans and animals.
For one, humans have their eyes set closer together than many other animals, which gives us wonderful depth perception. In exchange, we lose some of our ability to have good peripheral vision, the way cows do. (Did you ever try to sneak up on a cow? She may play it cool, but she knows you're there.) These two features give us binocular vision.
Find out more about this book:YOU: The Owner's Manual, Updated and Expanded Edition: An Insider's Guide to the Body that Will Make You Healthier and Younger