Headlight lenses are polycarbonate with a UV-protective coating. In Las Vegas that coating is under attack year-round — once it fails, the plastic underneath oxidizes, hazes and turns yellow.
The practical problem is light output. A hazed lens scatters the beam instead of projecting it, so light goes into the air and the roadside rather than down the lane. You may not notice the fade because it happens gradually over years, but the difference at night is real.
Restoration works when the haze is on the surface. Wet-sanding and re-clearing a lens can recover most of the clarity, and it’s the cheaper path. It holds up if the lens gets a proper UV clear afterward — a polish alone will re-yellow within a season here.
Replacement is the answer when the damage is deeper: crazing inside the plastic, internal moisture or condensation, a cracked lens, or a reflector that has gone dull. No amount of surface work fixes any of those.
Either way, aim matters. A new or restored lens that isn’t aimed correctly just puts the glare somewhere else. Have the beam pattern checked after any headlight work.
