Causes

• The acrylic plastic used in today's headlight lenses is much softer than the glass used in sealed-beam headlights, meaning that it can be easily scratched by deliberate damage, scuffing or even windblown sand.
  
  

Permanent Damage

• The rule of thumb is that if a scratch is deep enough to catch a fingernail, it cannot be buffed out and must be filled with plastic repair resin and sanded back down to its original state.
  
  

Polishing Headlights

• When using products designed specifically for plastic, the process of polishing scratches from a headlight varies little from that used to buff paint.
  
  

General Process

• Start polishing with a compound abrasive enough to leave a milky haze in the lens. Keep polishing with progressively finer compounds until you reach the finish you desire.
  
  

Repair Products

• Some repair products include Meguiar's Scratch-X, 3M Plastic Cleaner, 3M Plastic Polish and Polyhog's Headlight Restoration Kit, which includes all the compounds and buffing pads necessary to do the job.