What Causes Headlight Lens Deterioration?

Jun 24, 2020

What Causes Headlight Lens Deterioration?

Back in the 1980s, vehicle manufacturers stopped making headlights out of glass and started using polycarbonate or plastic for the lenses as it’s easier to manipulate to create the perfect shape for car design headlight shapes. Polycarbonate is a very light material that can be formed into many different shapes, its durable and doesn’t brake easy – the perfect substitute for glass! However, despite the versatility of this material, polycarbonate is prone to oxidation.

When your car’s headlights become oxidised, yellow and hazy it will give poor illumination for the driver and make it difficult for other road users to see you coming. It impacts your safety and the safety of other road users. So, what causes headlights to be fuzzy?

What causes headlight deterioration?


When your headlight becomes cloudy or have a yellowish tinge this is due oxidation caused by the UV rays from the sun causing the lens to develop micro-cracks, hastening the colour change.

Chemical build-up

During the winter months, there is dirt, de-icer and salt rapidly building up on your headlights causing a cloudy film. This will decrease your visibility and increase glare for oncoming road users.


The polycarbonate lens used in our headlights is porous and heats up from the sun as well as from the light inside. Over time, it will absorb dust and dirt particles through tiny weaknesses in the surface, causing it to appear cloudy. Therefore, when the bright light is trying to come through the semi-transparent lens, it’s refracted by these particles causing a major glare for oncoming drivers.

Atmospheric chemicals

Depending on where you are in the world, there will be a varying level of atmospheric chemicals and this can play a part damaging your car’s paint and the headlights.

Thankfully, you can restore fuzzy headlights and if you’re mechanically minded, you can even do this yourself at home! But if you’re not to confident at doing it yourself, you can consult a garage to do this for you. Find garages in your area today with MyCarNeedsA.com!


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