I've seen some products in stores that you can use to repair scratches in eyeglasses, but I don't know how well they actually work. It looks like a thick liquid gets into all of the scratch lines and dries clear. You can then wipe it with a special cloth for glasses and it looks almost new.
I need to find something to remove scratches from watch glass, because I'm always banging my watch against a desk or a door at work. Maybe one of the treatments in the article will work for me.