Ah, that sucks, I’d suggest to get some of the shelve as an emergency solution, but I know some countries don’t sell negative diopter lenses without a prescription. The issue is that polishing out those scratches even if it’s just the coating can change the lenses diopter value even by a tiny amount. This can lead to distortions or blurriness even if it looks perfectly smooth. Ask around some opticians, maybe they have a cheaper plastic replacement lenses or they can polish them out professionally for a fee. I know this sucks but I wouldn’t mess around with this on my own, it can damage your eyes in the long run.