What kind of bulb do you have? If you have a compact bulb, or your chameleon can get within 6 inches of the bulb it can cause eye issues. I suggest that if you have a compact bulb you replace it soon. She also might just have something in her eye, if it's dusty in the area her cage is in, it could just be that too. If you can't figure out why this keeps happening, I'd suggest that you mist it a little more often if you can. This will help wash out her eye, but don't mist her directly. I hope this helps!