Now that was something I thought of right away, but then dismissed. I knew lights could hurt their eyes, but mine is outside the tank and far enough away that it would never hurt her, but I just realized, when she goes to sleep, she climbs to the very top corner of the tank and just hangs from the wall all night as she sleeps. It's just a couple inches away from the light. Sometimes it's an hour or two before her lights go out, and it is the side that faces the light that is messed up...
It could be a coincidence, but it could just as easily actually be it. The lights are on a timer but next time she climbs up there and hangs from the top of the wall, I'll turn the lights off manually and see if she gets better. Not sure though, since she is asleep, her eyes are fully shut when she's there. Would the lights be able to hurt her through her eyelids?
Do you think the lights would cause the swelling? And if it is what's been wrong, do you think there has already been permanent damage done to her sight?