Headlamp lenses are made of polycarbonate and, at their heart, consist of carbon-oxygen and carbon-hydrogen bonds. Polycarbonate offers great advantages as a lens material as it is light weight, moldable, cheap, etc., but also has its disadvantages as stated above. The physical reason for the lens degradation has to do with the fact that the energy of UV radiation is close to the disassociation energy of the chemical bonds – hence, over long periods of time, the UV radiation causes the bonds in the polymer to ‘disassociate’…and this leads to oxidation. To protect headlamp lenses from fading, manufacturers typically apply a coating to the lens – a hard, scratch-resistant, UV protected layer. Lenses that are exposed to sunlight (and the elements) for long periods of time, however, will eventually occlude as this protective coating starts to fail.
Headlamp lenses on most cars that are over 2 years old will undoubtedly show some signs of degradation unless the car is maintained regularly or garage kept. There are a lot of products on the market to restore headlamp lenses to like-new condition…some of them fail miserably, while others are quite good. Situations will arise, however, where the lens suffers from severe damage, due to extensive UV exposure, and, as such, it can not be restored using the below methods and will need to be replaced. It is cheaper to try to restore them initially and if you fail then you can always buy new headlamp fixtures.
Headlamp restoration is not too difficult provided you have the right products and equipment. As with all detailing processes, start with the least aggressive method first! Here we discuss three methods, from least aggressive to most aggressive, that should enable you to restore headlamp lenses to like-new condition.
If your car's headlights have become dull, cloudy or yellowed, a headlight lens cleaner solution can add new life to them. Replacing an old set of headlights with a new pair can be expensive. So an inexpensive headlight lens solution kit that makes them look like new again is always a good idea. You might be surprised to learn that you can even buy a very high quality headlight lens cleaner at Walmart. To get you started, here is a list of some of the best headlight cleaning solutions.