I would use liquid lenses on light scratches. Anything else seems a bit overkill as liquid lenses has worked for me in the past. If I would recommend anything for a light lens scratch it would be liquid lenses as well. I, however, have never come across another liquid lens user.
Buffing the glasses is probably the easiest way, however, they make filling substances, that fill scratches. It is said by some that toothpaste works for this, applying a little, then buffing it out.
I've used a cerium oxide paste to polish out a scratch on a car windshield. It should work on eye glasses or a visor. But if the scratch or pit is too deep. you'll need to use a more abrasive grit.