Do Chameleon Eyes Work Together or Separately?
You already know that chameleons can change color to match their environment. But they have another weird skill — they can point each eye in a different direction, independently. With this they have an extremely wide field of vision, so they can perceive more of their surroundings with less body movement. This helps them be less visible to both their predators and their prey.
Look at his cute little chameleon eyes – he’s looking in two directions at once! Still, scientists have wondered whether chameleon eyes actually see two distinct views. To test this, researchers in Israel showed each of their chameleons a double image of an insect moving in opposite directions across a computer screen. The chameleon would focus one eye on one insect but let the other eye look around. Then, both eyes would focus on one insect very briefly and the chameleon would shoot out its tongue to try to catch it.The researchers concluded that the eyes were not acting completely independently. There seemed to be a need for them to converge on the target once the chameleon had decided to attack, in order to get the proper depth perception for success. Also, the second eye seemed to know where the first eye was looking, since it was able to swivel around very quickly to the same target. The researchers called this a kind of “cross talk” between the eyes.
As Professor Ehud Rivlin of the Technion-Israel Institute of Technology said, “Each eye is aware of its own location and the orientation of the other eye. It is just a different kind of cooperation that takes place in human binocular vision.”
A paper about the study appeared in the July issue of the Journal of Experimental Biology. — L.S.
Thanks, AllAboutVision for content.