I just repaired a pair of glasses using polyurethane glue. Carelessly, I neglected to protect the polycarbonate lenses, and one of them got a bit smudged with the glue. I wiped it immediately, so it was a very thin coating, but it left that part of the lens looking frosted. Google told me that acetone dissolves cured polyurethane, but it also dissolves polycarbonate, of which the lenses are made. What to do? I'm a metalsmith, and with the lens already damaged, I thought to give Sunshine cloth a try. It's fabric impregnated with a mildly abrasive buffing compound intended for spot-polishing of jewelry. After all, if it can put a mirror shine on metal, then why not polycarbonate? I started with the corner, and it looked good, so I continued. Within seconds (yes!), the frosty polyurethane residue was completely cleaned off, and the lens looked almost as good as new. In fact it looked so good, that I polished the entire lens with Sunshine cloth. Was I surprised! You don't have to believe me if you don't want to, and I can't say whether it would work for you, (I think it would depend on how deeply the acetone etched your lens.) Nonetheless, in this situation it saved my a**. https://www.riogrande.com/product/sunshine-cloth-single-pack/337039 https://smile.amazon.com/dp/B00S28IBUS/ref=cm_sw_em_r_mt_dp_U_nYPIEbABP5039
