Eye #1 Eye #2 Eye #3 Eye #4 Eye #5 Eye #6 Eye #7 Eye #8 Photos: (1) Animals Animals/© W. Gregory Brown; (2) National Zoological Park, Smithsonian Institute; (3) Alan H. Savitzky/Old Dominion University; (4) Animals Animals/© Michael Dick; (5) Visuals Unlimited/© Joe McDonald; (6) Visuals Unlimited/© Brian Rogers; (7) Corbis-Bettmann; (8) Rob and Ann Simpson/Visuals Unlimited.