It is not a the result of some other gene, all Albinos have this trait because all ball pythons have it. When Bob used to have the pics of the original Albino on his site you could see it in the pics of that animal.
If you look at the eye of any ball you will see that the top half is always a shade or two or three (or more) lighter than the bottom half because there is a pigment differential where the eye stripe passes through it. It is a bit more marked in Albinos because of the sharp contrast of their red eyes.