Some frogs have evolved eyes that are far too big for their bodies

By Christa Lesté-Lasserre

The Cameroon forest tree frog (Leptopelis brevirostris) has very large eyes

Christian Irian

Certain frogs have some of the biggest eyes of all vertebrates, relative to their body size, which is a significant evolutionary investment that has puzzled zoologists. Now, researchers have found that the eye size of these animals seems to scale depending on their environment.

Eyesight is costly in biological terms because it requires a lot of energy to function, which explains why animals living in dark environments like caves often evolve to have smaller eyes. That means big-eyed frogs clearly need the ability to see contrasts, details, …