What more, the vertebrate eye has a flaw: its blind spot. The fibers of the optic nerve and the central retinal blood vessels irradiate in front of the retina.

What more, the vertebrate eye has a flaw: its blind spot. The fibers of the optic nerve and the central retinal blood vessels irradiate in front of the retina. You may think that it is a necessary defect, but the squid eye, which evolved independently to end up almost identical to its vertebrate counterpart doesn't have it. The nerve fibers and blood vessels run behind the retina. http://en.wikipedia.org/wiki/Cephalopod_eye http://en.wikipedia.org/wiki/Cephalopod_eye