VIDEO - Do It Yourself Headlight Lens Polishing
This video from 3M shows how the do-it-yourselfer can take a bit of time and their polishing kit and restore the clarity to plastic headlight lenses. Milky or badly yellowed lenses turn crystal clear again as your electric drill does all the work. This promotes properly focused light that helps you see properly again, likely far less expensively than buying new lenses! You could also do turn signal and taillight lenses as well.