Quote Originally Posted by Pythonfriend View Post
i dont know much about this, just a few things i picked up, and i dissected the eye of a cow at school.

often there is a dark layer just behind the retina, where the light-sensitive cells are. the light goes in, gets focused by the lens on the retina, and now you dont need it anymore. instead of having it bounce all around, you absorb it with black pigment. many eyes have this feature, i am not sure if the human eye has it. after all, humans often have red pupils when photographed with flash.

in some animals its further developed, they really have a pitch black layer integrated into the eyeball. and some have a reflective layer, for improved night vision, between the retina and the black layer. cats. the eyes of cats, when they look at you, really reflect much of the light back to the point of origin, when you shine light into their eyes.

now its quite clear that BPs have that black layer in the eyeball. in some leucistic hatchlings you can see it through the top of the head. evolution typically goes for obvious solutions, re-uses things, so when you diminish body pigmentation, and the same pigments are also used in the eye, these will also be diminished. if that black layer behind the retina is not effective enough, you get the albino eyes with red pupils.

it also depends a lot on how the picture is taken, with or without flash. humans with red pupils in photos are so common that many cameras now automatically correct it. humans with actual red pupils in real life are rare, and limited to extreme cases of albinism, and even then it depends on lighting.

so, back to BPs. i see why leucistics of any kind, like black eye leucistics or blue eye leucistics or ivories, are more likely to have red pupils on photographs. the dark pigments in the eye are the same ones you are taking away from the rest of the snake. but in real life its most likely to be seen in albinos, unless you have a flashlight right between your eyes and point it at the eyes you are looking at.

so, much of it has to do with photography, and to answer the question, fire and yellowbelly still have plenty of dark pigment, while super fire and ivory seem to have serious trouble when it comes to producing dark pigment. in all cases, the red you see is the color of blood, from the many blood vessels the light passes through. if enough pigment is present, nothing comes back, and you have a black pupil. if pigment is too diminished, what comes back is red.

this is the same with many species. i hope that helps answer the question. keep in mind that in many pictures, the red pupils only show that the picture was taken with flash.
^ this guy knows his stuff, lol