Funny this came up. Just 3 weeks ago I bought a kit from Wal-Mart to fix one headlight on my wife's car.
We bought the car a few years ago, was a prior salvage. Was only called that because of hail damage, and that was repaired before we bought it, got a great deal. Anyway, they must have replaced the driver's side headlight because it looks brand new. The passenger side looked terrible and it only got worse over the last 3 or so years. I was in Wally World to get some other things and decided to look for a headlight resto kit. Picked this one
HERE
I did not take before/after pics, but please trust me that the headlight actually looked like the "before" part of the image on the box and like the "after" part when I was done. I was honestly amazed. And it was less than 10 bucks and no power tools.