How To Clean Oxidized or Foggy Headlights

For a while now, car manufacturers have been using a plastic instead of glass for car headlights. It’s lighter, less prone to damage, needs less care and of course, cheaper to manufacture, which when your manufacturing millions of vehicles each year, adds to up to significant savings.

Over time, the headlight lenses can be become cloudy, or tarnished, and while that isn’t a huge problem, it can lead to reduced night time vision, and in some cases, failure to meet regulations, so what can you do?

Headlight Oxidization

Before we get in to how to clean oxidized headlights, let’s look at why they get that way.

The main reason why headlights oxidize or ‘fog up’ is due to the UV (ultra-violet) rays from the sun. They attack the plastic and breakdown the surface coating, leaving microscopic pock marks – this has two effects: the first is that the natural pitting diffuses the light, making for dimmer viewing, but these pock marks get filled with naturally occurring debris which then can’t be cleaned with the usual methods, they need removing with a very mild abrasive.

The overall effect is that the headlight lenses will have a yellowish tinge to them, and if you run your hand across the lens, it will feel rough to the touch.

But it isn’t all bad news!

Cleaning Oxidized Headlights

Of course, you could always take your car to a shop to have the headlights professionally restored. The body shop will use a professional cleaning solution, and will have the correct tools to apply, polish, clean and seal the lens. If you don’t want to pay for a professional, there are plenty of home methods, including … toothpaste!

fix foggy oxidized headlights with toothpaste

Yes, toothpaste does work. Before you rush out and start applying that Colgate everywhere, you should know that only certain kinds of toothpaste work, and that while it will remove the oxidization, it won’t seal the lens to the elements afterward.

If you’re looking for a professional (or at least, semi-professional) clean up job of your headlights, you’re much better off buying a headlight restoration kit – there are plenty available. Some of these kits offer everything that you need, including a sealer for when you’re done, that way, you won’t have to worry about the lenses for some time to come.


washed and cleaned car

You should always start with a washed and cleaned car. Otherwise you’ll just be rubbing dirt around the headlight lens, perhaps making it worse – at the very least, wash the headlights before starting.

Depending on the kit, you’ll need two or three microfiber towels for the job. The first for applying the polish/paste, second to wipe it off and the third for sealing (if it’s separate).

We’d also recommend masking around the headlights with tape. You really don’t want to spot the paint with any harsh cleaners, a good quality masking tape is ideal.

tape masking headlights

Try not to leave it on for too long, as the adhesive could damage the paint.

Once you’ve masked off the headlights, it’s time to start removing the oxidization from the headlight lenses. Apply the polishing compound with a soft cloth, some kits say in a back & forth motion, whilst others will tell you to use a circular motion. For what it’s worth, we’d always just go in one direction.

You’ll start seeing the results on your cloth fairly quickly. Your towel will become dirty, but you’ll need to use some elbow grease to get the lens spotless. It can take up to around 25 minutes for each lens, and of course, how bad the oxidization is. For best results, keep turning the cloth and applying more cleaner if necessary.

As you’re working the cloth on the lens, the action of turning the cloth will help you to see the results, and start polishing the lens. Once it’s done, take a clean cloth for buffing up to a shine. If your kit includes a separate sealer, then this is the time to apply it, but if the cleaner itself seals the surface, then you should be done – one perfectly clean and oxidization-free headlight lens.

Routine Maintenance

Hopefully, you won’t have to touch your headlight lenses for years to come. A good tip is to just give them a light buffing every six months or so as part of your detailing routine – this should ensure that they never get too bad, or at least keep the oxidization away for that little bit longer.

In all honesty, there is nothing you can do to actually stop it happening for good. All you can do is help to keep it at bay, a little preventative treatment if you will.

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