From electro-sensory pores to top-notch noses, we hear a lot about sharks' finely tuned, prey-tracking arsenal. But one tool that's often downplayed is the eye. Despite their size and appearance, shark eyes aren't that different from our own. Look closely at this great white encounter from White Shark Video cameraman Andy Dellios, and you'll see the animal's inky blacks – often dubbed "lifeless" or "vacant" – follow the camera as the shark swims past.
"Eyeballed" by a great whitePeople sometimes ask if "sharks look at you". This great white shark is eyeballing WSV cameraman Andy Dellios the whole way. This clip also provides great detail of the ampullae of lorenzini, nostril, and scars of this big male white shark.
Posted by White Shark Video on Wednesday, January 13, 2016
While filming our Smithsonian Channel film, "Great White Code Red," sensory biologist Dr Craig O'Connell dissected a great white's eyeball to give us a better look at how these animals see.
"One of the most misunderstood aspects of a great white shark is its eyes," he explains. "They actually have pretty good vision. The anatomy of the eye allows them to see light, movement, colour, contrast and detail."
Much like in humans, a spherical lens within the eye can also be adjusted to focus near or far. But if shark eyes aren't as alien as they seem, how do these predators see at night?
This is where the great white's anatomy outperforms our own. At the back of the eye lies a layer of reflective cells, which helps the shark see in low light. "It produces 'eye shine' like you'd see in big cats," says O'Connell.
During the day, these cells are covered by pigment, but at night (or in murky conditions) the pigment retracts, allowing the mirrored cells to reflect light, and enhance the image.
To keep the sensitive organs out of harm's way, sharks come standard with protective eye wear. Most species rely on the nictitating membrane, a thin layer of tissue that can slide over the eye like a spring-loaded lens cap. Great whites, on the other hand, employ a different tactic: they can actually roll the eyes back, exposing a hardened, fibrous sheath that surrounds the lens. This so-called sclerotic coat is an invaluable adaptation – especially when the seals you eat can reach 790 pounds (360kg), and boast sharp teeth and claws for defence.
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