Hammerhead sharks may have human-grade vision with one major blind spot

2935553971_b4c86cf410.jpgA new study conducted in Florida has given scientists reason to believe that hammerhead sharks may have vision comparable to that of humans. The researchers measured electrical activity in the eyes of half a dozen sharks from three different hammerhead species. They then put electrodes under the sharks' corneas and recorded electrical activity while shining lights in horizontal and vertical arcs around each eye. Compared to normal-headed sharks, the hammerheads had three times the visual overlap — that's what creates stereo vision and depth perception in animals with eyes that face forward. This, of course, helps them be faster and more efficient at hunting prey. But there's a catch: because their eyes are so far apart, hammerheads have these giant blind spots right in the middle of their head. As study leader Michelle McComb put it in an interview with National Geographic:
There's actually been anecdotal claims by divers that they see little fish schooling right in front of the hammerheads' heads. It's like the fish are swimming by and saying, Ha, ha, ha, you can't see me!
Hammerhead sharks have "human" vision [National Geographic] Image via Eric Charlton's Flickr