The polycarbonate plastic headlight lens on your car or truck degrades from the moment it leaves the factory. Air pollution, airborne grit, and ultraviolet light take the shine off and then discolor the lens. After only a few short years, a haze develops across it. Fortunately, lens-renewal products–boxed kits consisting of abrasives that grind off the yellowed layer and smooth out scratches–are fast and easy to use. Some also contain a UV-resistant coating that you wipe or spray on.
How We Tested
We performed two tests. One test was on cars that exhibited moderate lens degradation, but we also paid a visit to our favorite auto salvage-recycling yard, Scarpati’s in Trenton, NJ, and asked to pick out three badly degraded headlight assemblies. They thought we were crazy, until we explained what we were working on. Our tests showed that lens restoration products quickly restore a dulled, yellowed, and scratched lens. They can’t address dust, condensation, or sunlight-related degradation on the inside of the lens or on the reflector. And we can’t make any estimates as to how long the improvement lasts. That depends on the region in which the car is located, the sunlight it sees, the extent of the air pollution, and how dusty the driving conditions are.
As to specifics of the procedure we used, it was pretty simple. All of the lenses were first cleaned with water or household spray cleaner to remove dirt. Then we applied the products strictly per the instructions. No two headlight lenses were identical, of course. If you look carefully, you can even notice differences on the same car. Still, we think we have a clear idea of how these products work and what they have to offer. We called the results as we saw them after rigorous testing and analysis.