Recent research indicates there's more to penguins than meets the eye.
If you've every wondered what it would be like to be able to see as clearly under water as you can on land, just ask the nearest penguin. Most aquatic animals are short-sighted on land. But researchers have discovered that penguins can apparently see equally well in both environments because of the unique structure of their eyes. Penguins have to be able to see well under water because their diet consists mainly of plankton, molluscs, crustaceans, and the inevitable fish. Through a special slowing-down of their heart rate they are able, like many other diving animals, to stay submerged long enough to search out and chase whatever catches their fancy.