Headlights have a protective coating which acts like lacquer on paintwork. It is there to protect the underlying plastic from degradation from UV rays and other environmental factors that could otherwise degrade the surface.
However, due to the lack of care that headlights receive, the coating on the headlights, although does a very good job itself, does breakdown over time.
This results in the headlights turning yellow, cracking and turning very dull which in turn inhibits the amount of light passing through, in short means your headlights become less useful and you end up not being able to see where you are going..
In order to look after your headlights you must pay them as much attention, if not more, than the lacquer on your paint.
What To Do
To keep your headlights well protected against UV, ensure you are protecting the lenses at least as often as you protect the paint, or every 3 months if you are unsure. Although if you don’t wax that often it is unlikely that you are googling how to look after your headlights!
What To Use
If you are protecting your headlights at the same time as your paint, then use the same wax or sealant on your headlights. Most (read all) waxes and synthetic sealants will contain UV inhibitors and will protect your headlights from the elements and due to the similar chemical compound between headlights and lacquer (mainly acrylic), they will all be safe to use and not cause any irreversible damage.
A great wax to use is Autoglym High Definition Wax for very good durability and outstanding looks on any type of paint, and very good for headlights due to its protection against the elements.
If you prefer something more specific then try:
The Meguiars PlastX is a very easy to use plastic polish whilst adding protection to maintain an as-new look.
After waxing, make sure you do not use a local hand car wash due to the strong traffic film removers they use which will degrade any wax you put on the headlights.
Instead use a wax-friendly shampoo like:
Headlights Need More Than A Wax?
If you’re headlights have turned yellow, started cracking or badly faded then some professional help may be needed in order to restore them safely and effectively.
Our professional headlight restoration in Surrey offers a convenient and hassle-free solution to making your headlights look like new.