Why Do Headlights Get Foggy? – Here’s Everything You Need To Know

Last Updated on October 4, 2021 by

Automotive headlights may get foggy for various reasons, including oxidation due to exposure of the polycarbonate lens to air. High moisture content in the air may also lead to the creation of vapor in the headlight box. This water vapor will then scatter the light coming through the lens leading to fogginess. 

The water vapor inside the headlight box will create patterns and diffuse the light on the road, which will make it hard for the motorist to see. 

What Are The Other Causes Of Fogginess On The Headlights?

Other Causes Of Fogginess On The Headlights

Besides oxidation and water vapor on the headlights, there are other causes of fogginess, including;

Damaged Road

Driving on a damaged road is another factor that contributes to your headlights getting foggy. As you drive, debris and small rocks are thrown onto the polycarbonate lens of the headlight, causing pits and dents on it. These dents will gradually make your headlights yellow and foggy causing your visibility on the road to be poor.

Chemicals And Dirt

Driving on the road for long will expose your car to dirt and other chemicals. These substances will gradually develop a thin opaque layer over the headlight lenses. The cloudy layer dims the lights and makes it hard for the headlights to see clearly. 

How Can You Prevent Your Headlights From Getting Foggy And Yellow?

You can protect your headlights from fogginess if you do the following simple tasks;

Parking Your Car Under The Shade

One of the main reasons your automotive headlights get foggy is oxidation due to exposure to the air and direct sunlight. You can prevent this by parking your vehicle under a shady tree or in the garage. You can also ensure that the headlight is not facing the direction of the sun. Doing this minimizes the exposure to ultraviolet rays and hence slows down the oxidation process. 

Polishing Your Headlights

If you notice any early signs of yellowing on your headlights, you can polish them to remove and prevent more fogginess. To do this, get a clean microfiber cloth and apply a non-abrasive polishing medium. Use it to polish the lenses and remove any visible yellowing. 

Cleaning Your Car Regularly.

Make sure that you wash your car headlights with automotive soap cleaner at least every three months. Doing this will help remove any chemicals and dirt that are responsible for promoting fogging. 

Are There Any DIY Treatments For Foggy Headlights?

DIY Treatments For Foggy Headlights

Yes. Several DIY methods are available for treating foggy headlights. You will first need to use an automotive soap to clean the lenses to give them a clean surface. Once the lenses are clean, you can use one of the following techniques;

Using Vinegar

White vinegar is a great DIY home remedy that helps to restore your headlights without much struggle. Place some white vinegar in a container (a basin will work well), then soak the lenses in the liquid after removing them. Use a rough sponge to rub away any grime on the lenses and reinstall them when you finish cleaning. This simple home remedy helps your headlights to look as good as new. 

Using Baking Soda

A baking soda paste is another very effective substance that helps remove fogging on your lenses. To make the paste;

1. Put around five tablespoons of baking soda in a bowl, then add enough water. Mix carefully with a wooden spoon or a stirrer to make a paste

2. Using a sponge, apply the paste liberally to both headlights polishing with small circular motions. Leave the paste to sit for a few minutes, then rinse with clean water to reveal the results. 

Application Of Toothpaste

Toothpaste is another inexpensive and readily available substance that will help clear yellowness from your automotive headlights. Apply this product directly on each lens using a soft dry cloth as you scrub lightly. Leave it for a short while before rinsing the toothpaste away and enjoy the new look on your headlights. 

Sanding The Headlights

This process may require the services of a professional since you don’t want to ruin your lenses. An expert will know the right sandpaper to use and the correct procedure to follow. This method involves;

1. Using water and soap to clean the headlights and their surrounding surfaces

2. Remove any grime from the exterior housing to avoid scratching the lenses

3. Dry the cleaned parts to ensure that there will be no moisture on the headlights during the restoration process

4. Using painter’s tape, cover the surrounding parts of the headlights and be sure to leave the housing exposed. Do not use more adhesive tape as this may damage your car’s paint

5. Apply some little water on the sandpaper (start by 800 grit paper) and move it lightly in circular motions around the headlights 

6. Using finer sandpaper (1600 grit and above), repeat the process, but start from the opposite direction. 

7. Place some rubbing alcohol on a soft piece of cloth and wipe off the headlights to dry them

8. While the headlights will look clear, you need to polish with some toothpaste or a specialized headlight polish to give it a final touch

What Are Some Of The Hazards Of Driving With Foggy Headlights?

Besides a car with foggy headlights looking unattractive, they are also a hazard. Here are some of the reasons why you need to clean your headlamps;

1. Foggy headlights make it difficult to drive at night since they do not put out enough light.

2. Fogginess will affect the distribution of light on the headlights. Foggy headlights give out light at angles, and this will be dangerous for other motorists.

3. Fogginess may damage the headlamps since they absorb heat energy from the light and get quite hot.

4. Foggy or yellow headlights lower the value of your vehicle, especially if you plan to sell it in the future.


There are many reasons why your car headlights get foggy, as stated above. Foggy headlights make it difficult for you to drive at night due to poor visibility and can lead to accidents. Yellow or foggy headlights will also make your car look unappealing, and it is necessary to clean them and restore the great look. By following the above steps, you will easily wash your headlights and give your car a better look.  

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