Quote Originally Posted by Shelby
Many snakes have a stripe that is on their skin that goes through the eye. It is there to camoflague the eye and to break up the outline. They can sneak up on prey and avoid predators easier that way.

It is pigment, not the pupil. If you shine a light (not too bright!) in the snake's eye, you can see the pupil contract.

Red tail boas have a very prominent eye stripe
Shelby, I borrowed this from another thread. In one of my longings over the RTB I am looking at, I noticed this. I really thought it was cool, one of the things I like about it.