Yeah, I worked at an optical lab to pay for college. We'd have customers come in with screws that wouldn't stay in so we'd use clear nail polish. I'm sure for some uses, loctite would be better, but nail polish does very good. We'd also use it on metal temple pieces when someone's facial oils had done a number on it. We'd buff the pieces smooth and coat with clear nail polish. Not a perfect fix, but would get someone who could afford new glasses by for a while longer.
