How To Restore Your Car’s Headlights, And Why Do They Go Dim?

We’ve been there. You’re driving along at night, and you’ve noticed your car’s headlights seem to have dimmed so much that you may as well strap a candle to your bonnet.

Although this isn’t so much of a problem on modern cars with ultra-bright LED lights, those of you still running halogens likely will have noticed some degradation. New bulbs might help, but those aren’t always to blame. 

So why do your headlights dim? We explain what happens, as well as why you should restore them.

Why do car headlights dim over time?

Pretty much every car produced in the last handful of decades will use clear plastic lenses for headlights instead of glass. To help protect them from the elements over time (think UV rays, debris on the road), they tend to have a clear plastic film placed over them.

Useful, but that comes with a downside. Over time, this plastic coating begins to degrade, leaving car headlights with a foggy, yellowish tinge. Not only does it look a bit rubbish, but it can also have an effect on the level of light passing through from your headlight bulbs.

How can I restore my headlights?

Fortunately, restoring your headlights to a like-new state is pretty easy to do today. We’d recommend a few things to have to hand.

• Sanding and finishing pads

• Headlight restoration-specific polish

• Automotive masking tape

• Microfibre cloths

• A drill, if you have one

You can buy kits that will contain many of these items, which should give you a helping hand. Like these from Holts and Meguiars, for example:

Holts Headlight Restorer Kit

This kit will be most effective if you have a drill to hand, as it includes a mechanical polishing head and a 75mm drill adapter plate. Eight abrasive papers are part of the package too, along with liquid polish and microfibre cloths.

Buy it at Euro Car Parts

Meguiars One-Step Headlight Restoration Kit

If you’re doing things by hand, this one from Meguiars may be more useful. With polisher and abrasive pads included, it’s a handy little kit for quick-fire restoration.

Buy it at Euro Car Parts

Step 1: Preparation

This is where your masking tape comes in. Make sure to tape over the exposed paint surrounding your headlights to reduce the risk of causing damage while you’re working away. It only takes an accidental slip to inadvertently scratch your paint, so this bit is important.

3M Performance Industrial Masking Tape

Buy it at Euro Car Parts

Worth giving your headlights a quick clean at this point with a microfibre cloth, too, just to make things easier. We’d suggest you keep a spray bottle of clean water on hand if you can, too, just to keep the headlight a little damp as you sand it.

Step 2: Sanding

We’d recommend following the manufacturer's instructions on which abrasive pads or sandpaper to use to start sanding, but you’ll want to do this before applying any polish.

Make sure to sand the whole headlight for an even finish, and make sure to keep the headlight a little moist with a gentle spray of water to keep things moving smoothly.

Step 3: Polishing

Once your headlight is sanded, you can apply your polish. If you’re using a drill, we’d recommend applying this to your compound pad and giving it a gentle coat without turning the drill on to start with.

Patience is key, here. Start slow with polishing (be that with your hand or gradually increasing the speed of your drill) and making sure to cover all areas of the headlight. Keep going until your headlights shine and look new.

Give them a gentle clean, remove the masking tape, and they should be good to go.