Expert: Walter Hintz - 11/18/2007

Question
I've always assumed that human vision was about  average by comparison to other animals, but I recently read somewhere (re a page on Cerenkov radiation) that, in fact, human vision "peaks at" the colour green, and is relatively poor at perceiving the violet range of the spectrum. Is the human eye also poor at perceiving red colours as well, by comparison to other animals?

Lastly, do any species of animals exist which can perceive all parts of the visual (human) spectrum plus the infra-red and ultra-violet range? If so, please give me some examples - (I presume that no species can actually see x-rays, microwaves and other more extreme ranges, though a tiny number might(perhaps?)  have specialised organs which sense some such rays).
Thanks,
Geoff

Answer
Comparing color vision between humans and other animals is difficult since we cannot easily test what they see. Normal humans can perceive about a million different colors that exhibit wave lengths between 380 and 750 nanometers
 Complexity in color vision varies in the animal kingdom. Strangely enough a complex system exists among the Stomatopods (Mantis shrimp)
Most mammals do not have color vision. Insects cannot see at the red end of the spectrum but can detect wave lengths at the UV end. I believe you assume correctly that wave lengths at the extremes are nit vision related.
 I would like to refer you to this sight that may answer some of your questions
webvision.med.utah.edu/colorbl1.htm