If You Swapped Your Eyes With An Eagle!!!!

If you swapped your eyes for an eagle’s, you could see an ant crawling on the ground from the roof of a 10-story building. You could make out the expressions on basketball players’ faces from the worst seats in the arena. Objects directly in your line of sight would appear magnified, and everything would be brilliantly coloured, rendered in an inconceivable array of shades.

The more scientists learn about eagle vision, the more awesome it sounds. Thanks to developing technologies, some aspects of their eyesight may eventually be achievable for humans. Others, we can only imagine.

Eagles and other birds of prey can see four to five times farther than the average human can, meaning they have 20/5 or 20/4 vision under ideal viewing conditions. Scientists have to cook up special experiments to judge eagles’ eyesight — your optometrist’s alphabet eye charts are of no use, after all — and one common setup involves training the birds to fly down a long tunnel toward two TV screens. One screen displays a striped pattern, and the birds get a treat when they land on it. Scientists test their acuity by varying the width of the stripes and determining from what distance the eagles begin to veer in the correct direction.

According to William Hodos, a distinguished professor emeritus at the University of Maryland who has studied the visual acuity of birds since the 1970s, two eyeball features confer eagles’ sharper vision. First, their retinas are more densely coated with light-detecting cells called cones than human retinas, enhancing their power to resolve fine details just as higher pixel density increases the resolving power of cameras.

Second, they have a much deeper fovea, a cone-rich structure in the backs of the eyes of both humans and eagles that detects light from the centre of our visual field. “Our fovea is a little shell or bowl, while in hawk or eagle it’s a convex pit. Some investigators think this deep fovea allows their eyes to act as a telephoto lens, giving them extra magnification in the centre of their field of view,” Hodos told Life’s Little Mysteries.

On top of sharp focus and a central magnifier, eagles, like all birds, also have superior colour vision. They see colours as more vivid than we do, can discriminate between more shades, and can also see ultraviolet light — an ability that evolved to help them detect the UV-reflecting urine trails of small prey. But there’s no way to know what these extra colours, including ultraviolet, look like. “Suppose you wanted to describe the colour of tomato to someone who was born blind. You couldn’t do it. We can’t even guess what their subjective sensation of ultraviolet light is,” Hodos said.

Source: livescience