The Only Vertebrate That Can Move Its Eyes Independently Is The?
When it comes to curiosities in the animal kingdom, you’ll often find that when an animal is unique, it’s unique in a multitude of ways. Such is the case with the chameleon, a creature who doesn’t just have its famous camouflage, but comes with a veritable list of interesting features.
First, chameleon eyes have a negative lens (the surface curves inward instead of outward like our own) which allows it a degree of magnification higher than any other vertebrate (when adjusted for the size of the eye). By contrast, its cornea is positive, again aiding it in more precise focusing than we could muster. It also has eyelids fused to its pupils to protect the eyes, leaving only a small part exposed.
All those things are interesting, but what makes for the most unique thing about the chameleon’s vision is that it can completely move each of its eyes independently of the other, giving it an enormous advantage in that it can look nearly completely around its entire body to search for prey and watch out for predators. Not only does the increased field of vision help it, but by moving its eyes instead of its head, it is able to stay extremely still with minimal body movement even while looking over vast areas in the process.