On work glasses, that I didn't care about too much, I was able to bring them back using a super fine rubbing compound. In this case 3m perfect it compound. It took more than a hour, total, I applied using a soft rag. Took some time, but it worked. If you do it too much, (like the fourth time) though, you "sand" right through the coating thats on the outside... Made the lens look funny if you looked really close, but the scratches were gone.