light can hurt anythings eyes if to close..
There have been people that always use UVB there are a few threads..
yhere is NO adverse effects to this.. unless they are albino. and even still i dont know if there is any proof that it is bad for them.
Ive heard of a few studies done on bearded dragons, not leos.
I assume the same eye problems could happen, maybe worse, especially because they are nocturnal. But I dont know myself, so I avoid UVB.