Ever wanted to have X-Ray vision? Wanted to be like Superman and be able to see through buildings and all across the world? Wanted to be like young Clark Kent, and see in to the… never mind. Well according to scientist at Rensselaer Polytechnic Institute, we do have X-Ray vision, just not how you imagined it.
Mark Changizi, assistant professor of cognitive science at Rensselaer, is the man changing your dreams of X-Ray vision. He believes that, in addition to our two forward-facing eyes allowing us to see the world in 3-D, they also let us see through things; some things.
Most animals have existed in a non-cluttered environment, and like the horse, rabbit, birds or fish, developed eyes on the side of their heads. The sideways facing eyes allow these animals to see a larger array of things, including behind them. This is known as panoramic vision.
However for some animals, humans and other large animals predominantly, we’ve lived in a cluttered environment, such as forests, with leaves and trees every which way. Subsequently, we developed two eyes that faced forward, and while that loses us the ability to see behind us, according to Changizi, it allowed us to see through things, like the leafy environment of a forest.
This is called the binocular region, and all animals have at least a small binocular region, and it grows the closer together the eyes get. Many children will discover this region without knowing what it is they are discovering, when they hold up a finger or a hand, and close one eye, then swap, then swap back. They see the hand shift and they see the hand block what it is ahead of them. But with their eyes open, both eyes are able to see through the hand, so to speak.
"Our binocular region is a kind of 'spotlight' shining through the clutter, allowing us to visually sweep out a cluttered region to recognize the objects beyond it," says Changizi, who is principal investigator on the project. "As long as the separation between our eyes is wider than the width of the objects causing clutter — as is the case with our fingers, or would be the case with the leaves in the forest — then we can tend to see through it."
Changizi studied 319 species of animal over 17 mammalian orders, to discovery which animals have this ability. He looked at their eye position, and found it depended on two variables: the clutter in the animal’s environment, and the animal’s body size relative to objects creating said clutter.
"This X-ray vision makes it possible for animals with forward-facing eyes to visually survey a much greater region around themselves than sideways-facing eyes would allow," says Changizi. "Additionally, the larger the animal in a cluttered environment, the more forward facing its eyes will be to allow for the greatest X-ray vision possible, in order to aid in hunting, running from predators, and maneuvering through dense forest or jungle."
Possibly the most interesting factoid to come out of Changizi’s study, is the possibility of human change in the future.
"In today's world, humans have more in common visually with tiny mice in a forest than with a large animal in the jungle. We aren't faced with a great deal of small clutter, and the things that do clutter our visual field — cars and skyscrapers — are much wider than the separation between our eyes, so we can't use our X-ray power to see through them," Changizi says. "If we froze ourselves today and woke up a million years from now, it's possible that it might be difficult for us to look the new human population in the eyes, because by then they might be facing sideways."
Posted by Josh Hill.