I think he was asking if the paint was on the inside, would the glasses be wearable? To answer that question, yes and no. I know the clear coat would protect the paint but at the same time, if worn frequently sweat and oils could eventually eat it away which is why I prefer only doing exterior painting.
i splatter the inside of my frames, and the clear coat holds up very well with constant use. i use my custom splatters extremely often, so no worries abt the paint running at all. =)