Dim Headlights

Am I suffering from nyctalopia or are my headlights dim? The older I get the harder it is to see while driving at night, and I’m not alone in this. Customers frequently ask, “How can I make my headlights brighter?” In this short article we’ll cover how to make your headlights brighter so it’s easier to see at night.

Why do headlights get dimmer over time?

It’s not that your vision is getting worse. Well, it’s not only that your vision’s getting worse. Headlights do get dimmer over time. Why? There are usually two culprits that account for most of the problem.

  1. Halogen and HID bulbs get dimmer over time
  2. Nearly all headlight lenses are made of plastic, and plastic will get cloudy over time.

Halogen & HID headlights getting dimmer

I’m not a scientist, but I have removed a whole lot of headlight bulbs over the years. When a bulb is new, you can look through the glass because it is perfectly clear. As bulbs age there is a build-up of vaporized filament material that is deposited on the inside of the bulb. Most burned out bulbs have a shiny silicon gray color that is nearly completely opaque.

What about used bulbs that haven’t burned out yet? Well, sometimes those also have that opaque coating, and it blocks light, making the bulb dimmer. I also imagine that as the filament gets thinner as it vaporizes, increasing its resistance, decreasing its current flow, and therefore making it glow more dimly.

Am I 100% sure about the mechanisms that cause the headlights to dim? No. However, I am sure they do dim and my theory seems pretty plausible to me. If this is your field, feel free to contact us and set me straight.

Cloudy Headlight Lenses Causing dim lights

When your car was new the headlight lenses were nearly perfectly clear. Photons flew past them and bounced off the deer standing in the road, allowing you to see and avoid said deer. When the lenses get cloudy, the photons hit the lenses, which makes the lens very easy to see, but also makes the road a whole lot harder to see.

Consumer reports published an article about a AAA study a couple years ago, titled “Old Headlights Can Be Dangerously Dim, Study Finds

How to fix dim headlights

A New Car

So this suggestion is a little tongue in cheek. Most people aren’t going to want to spend $35,000 for brighter headlights. However, some new cars have insanely good headlights. The new generation of LED headlights work really really well. Far better than previous champion of brightness, the HID. If you’re really Mr. Magoo-ing it around town at night, you might want to consider a new car. Not only do they have headlights that turn night into day, they also have all sorts of sensors that can “see in the dark” using lasers, sound, and radio waves to help you navigate safely.

Replace your headlight bulbs

If your headlight bulbs have been in use for a while, replacing them will give you some more light. But why stop there? Just because your car came with basic halogen bulbs doesn’t mean you have to keep using the same thing. There are a number of “better” direct-fit options. Why is better in quotes? Well, there are some trade offs.

First, there’s cost. A standard halogen H11 bulb is $11. Sylvania’s current top-of-the-line H11 bulb is $65. Well, it’s six times as expensive, but at least the bulb will last longer? Unfortunately, no. It’s just like the saying about candles: twice as bright, half as long. There are also sometimes issues with melting headlight connectors due to increased current draw through a connector designed for lower current. Is it worth it? It’s up to you, but it’s cheaper than a new car and a whole lot cheaper than hitting a pedestrian.

Polish or Replace Your Headlight Lenses

We used to offer this service, but don’t any more. It’s low skill and labor intensive. We were barely breaking even, mechanics didn’t like doing the job, and many customers thought our prices were too high. We figured that if all parties were unhappy, it would be better to stick to our primary business.

However, just because we don’t do it doesn’t mean it’s not a good idea. If you’re handy and have an hour or two to spend on a project, polishing headlights is something you can do yourself. Just remember to protect the painted surfaces and that the work you put into sanding, the better the result will be. Sylvania kits are the best ones we found and you can purchase them on Amazon. If that doesn’t appeal to you, many body shops also do headlight polishing.

New lenses are always going to be clearer and stay clearer longer than reconditioned headlights, but they can be really expensive. On most cars the front bumper must be removed and the headlights aimed after replacement, but most of the cost is the light itself. Cheaper headlights are around $250 each and some are nearly $2000 each.

Take Care of your windshield

While it technically won’t do anything for your dim headlights, a dirty windshield certainly makes it harder to see at night. The same is true for old windshields. Gravel, rocks, and other debris kicked up from the cars driving in front of you will put little barely-visible chips in your windshield over time. If you’ve ever had a new windshield installed, you may remember how “bright” the world was when you picked your car up.

Switch to LED headlight bulbs

This is my least favorite suggestion. However, some LED bulbs that are designed to fit where a halogen bulb was installed do work fairly well. Why don’t I like them?

  • Janky installation schemes. Huge heat sinks that don’t fit in the available space. Low quality connector adaptors. Excessive weight that causes the headlight housing or bulb retaining clip to fail.
  • Difficultly finding replacement parts. You may find there’s no way to identify the bulb installed, or the company or re-brander may no longer be in business.
  • Low quality and / or low output. If there’s a way to determine which LED conversions are good and which are bad, I don’t know it. There’s a huge number of options available on Amazon and EBay, lots of fake reviews, and hit and miss results.

Headlight bulb installation

Installing a headlight bulb yourself is possible, but whether it’s a good idea depends on your skills and the car. Some cars are very easy. Some cars are very difficult indeed. Most of the time you won’t be saving a lot of money. We charge for 6 minutes of labor to install a bulb on 95% of the cars we work on. However, if you have the DIY spirit (and good for you!), here are some tips.

  • YouTube is a great resource for quick how-to videos if you’d like to replace your own bulb. It will also give you an idea if you have one of the easy cars or difficult cars.
  • Don’t go crazy yanking on the connector. Some headlight bulbs are held in place with flimsy spring clamps which can break off, requiring replacement of the headlight housing. When possible, support the bulb with one hand and the connector with the other. Be sure to press the connector release hard enough that it actually releases.
  • Be sure the new bulb is clocked into the housing correctly and is sitting flush. We’ve had more than one customer that has melted an expensive headlight housing by putting the bulb in incorrectly.
  • If you get stuck, get help. There’s no shame in asking someone who has done the job before to show you how it’s done. Next time you’ll know.


As I mentioned earlier, we don’t offer headlight polishing here anymore, but it’s not rocket surgery, so it’s a great DIY project if you have the time and inclination. We’ve polished hundreds if not thousands of headlights, and we learned a bit along the way. Here are our tips.

  • All kits are not equal. We like the Sylvania headlight polishing kit (and no, that’s not an affiliate link). Follow the instructions carefully.
  • Use a garden hose or plant sprayer and keep everything wet while sanding. More water = better.
  • Spend the time to do a really good sanding job, especially with the coarse paper. You want to remove all of the oxidation before moving on to the next steps.
  • If one headlight is worse, start with that. It’s easy to lose motivation after sanding for a 1/2 hour straight. Attack the worst headlight while you’re fresh.
  • Tape off the area around the headlight. The sandpaper will damage the paint.