Why Your Cars Headlights Get Foggy (And How To Fix It)

Generally, when you think of a part of your car fogging up, your windshield is probably the first thing that springs to mind, right? Indeed, in the right temperature conditions, such fogging is very noticeable and inconvenient. However, there's another aspect of your car that's equally susceptible to fogging, and unlike with your windshield, you may not notice it until it's already a problem — your headlights.

It's possible for your headlights to fog up after multiple years of usage, leaving you with cloudy lenses. Not only are these cloudy lenses generally unpleasant from a style point of view, but they're potentially hazardous to your driving experience. After all, cloudy lenses don't project as much light, which is the entire point of your headlights. If your headlights aren't working when you need them, you could find yourself driving into something you'd rather not on a stormy day or in the dark of night. So, how does this headlight fogging occur, and more importantly, what can you do about it?

Why do your headlights get foggy?

Most commercial headlights are constructed of a clear, shatterproof plastic designed to make them equal parts transparent and sturdy. In addition to that, most headlights are treated with a UV film coating to make them more resistant to intense heat, both from ambient sunlight and their own powerful bulbs. However, there are two weaknesses in this construction.

First, like most forms of plastic, the stuff used to make headlights is slightly porous, allowing little bits of dirt, dust, and other assorted crud to get trapped within them. Secondly, the UV film gradually wears down over time from heat exposure and general wear and tear, baking the plastic from the inside and outside simultaneously.

Put those two factors together, and you end up with a cloudy lens that has a severely diminished lighting output. Depending on how long the headlights have been like this, you may be able to just wipe some of the crud off, but in all likelihood, it'll be stuck fast.

How to fix foggy headlights

If you believe your foggy headlights are the result of simple wear-out, your best option is to visit your local car dealer or mechanic and either ask for service or full replacements, depending on your price range and their recommendations. However, if your car is relatively new and your headlights haven't been subjected to any particular abuse, you may be able to clear off the fog on your own.

If you visit your local automotive store, you may be able to find a headlight restoration kit, which includes a bottle of cleanser and some tools. If you can't find that, you can also try some household cleaners like baking soda mixed with water or toothpaste. You'll also want some towels, some latex gloves to protect your hands, a bucket of water, some generic surface cleaner, and a soft brush for scrubbing.

  1. Wipe down the surface of your headlights with the generic cleaner to get rid of any surface-level dirt.

  2. Wipe down the headlights with a towel until they're dry.

  3. Apply the cleanser/toothpaste/baking soda paste to the headlights in a thick layer and leave it for a few minutes to dry.

  4. Gently scrub the cleanser off the headlights with a brush.

  5. Clean off any excess with a clean towel and water.

Your headlights should be sparkly-clean once again. If your restoration kit came with some UV wax, apply that after cleaning to give it some extra protection.