the eye was a test case for natural selection; and for Helmholtz, it was a brilliant compromise — a flawed device to a brass and glass instrument-maker, but a structure nonetheless capable of ...

So, at the outset, nocturnal eyes gather more light than human eyes ... The retina is an extremely complex structure. It's made up of at least 10 distinguishable layers, and is packed with more ...

Difficult, but not impossible. Scientists have come up with scenarios through which the first eye-like structure, a light-sensitive pigmented spot on the skin, could have gone through changes and ...

This 2013 astronaut photo shows a giant eye-shaped impact crater in the Sahara Desert that is slowly being circled by ...