Pit vipers have primitive IR detection. "Eye" is a bit of a stretch, since it can't do any imaging. It's not a general capability of snakes.

About the horse eyes ... Predators often have eyes in front, since they need depth perception. Prey often have eyes on the sides so it's harder to sneak up on them.

Octopuses don't have the blind spot mammals have since their nerves are behind the retina, not on the front of the retina.

Humans with normal color vision are trichromats. Some birds, fish and other non-mammals are tetrachromats. Some human females may be tetrachromats.

That's all I got.
- mark 12-25-2012 4:35 am





add a comment to this page:

Your post will be captioned "posted by anonymous,"
or you may enter a guest username below:


Line breaks work. HTML tags will be stripped.