As I know that most of the lenses are manufactured with anti-scratch coating, that is to say, maybe the lenses on your glasses are all without anti-scratch coating when they are chosen and being processed. If you really want to add anti-scratch coating on your lenses, the best way is to change for another lenses.
Yes. You can take your glasses back to the place where you bought your glasses and ask them to add anti-scratch coating to your lenses. They will send your glasses to their lab and the technician will do it for you. It may take you some time to get your glasses back.