Back to all

See the Light (Automatic High Beam Dimmers)

December 8, 2024

It's happened to all of us.  We're driving down a highway at night and over a crest appears a car with its high beams blazing.  You are momentarily blinded, hoping the other driver will switch them to their low beam setting and restore your vision.

Not only do we not appreciate being blinded, face it; we don’t want to be that other driver, either.  You know, the one who forgets to turn down their high beams.

Why do we want high beams in the first place? They can improve safety when used correctly, giving drivers more reaction time since they can see farther down the road.  But research has found many drivers either don't use them or, when they do, they frequently forget to switch to low beams.  Enter the automatic high-beam dimmer.

The quest for the perfect one began back in the 1950s, General Motors invented something it called the "Autronic Eye." It was a phototube which sat on the dashboard and turned down your beams when it saw other headlights.  While touted as being the biggest advance in night driving safety in 30 years, it didn't work all that well.  But as technology got more advanced, systems improved.

Today's automatic high beam dimmers usually have a camera in the rear view mirror (pointing forward).  When the camera sees lights, software in the system's computer attempts to determine the source of the light, whether it is an oncoming vehicle, taillights, ambient city lights, street lights or the reflection off of a street sign.  It then adjusts the headlights to operate high beams if appropriate or a less-blinding mode if they’re not.

Some automakers are striving to make their headlight systems smarter and safer by developing lamps that can avoid blinding oncoming drivers by means other than simply dimming them. One idea? Splitting the beams so they will block just the portion that shines into the eyes of oncoming drivers.

It's a long way from the Autronic Eye. 

Perfect Tune Auto Repair
5434 S. Old US Highway 23
Brighton, Michigan 48116
810.227.9903
http://www.perfecttuneautorepair.com

Need Service?

Request a Quote

More articles from Perfect Tune Auto Repair

Tire or Re-Tire? (Getting Tires Ready for Hot Weather)

April 19, 2026

Heat isn't easy on vehicle tires, and as the seasons change, make sure yours are ready to take the heat. Let's talk first about inflation. Heat causes air to expand, so heat alone can raise the pressure in your tires. If you are driving on overinflated tires, they won't have as much contact w... More

Perfect Tune Auto Repair Tire Safety: Washington vs. Lincoln

April 15, 2026

Welcome to the Perfect Tune Auto Repair automotive blog. Today, let's talk about the effect of tire wear. Let's focus on stopping in wet Brighton conditions. In order for a tire to have good contact with the road, it has to move the water out of the way. If it can't move the water, the tire w... More

Passing the Test (How to Prevent Emissions Test Failure)

April 14, 2026

Vehicle emission testing has become ubiquitous in North America and for a good reason. Clean air quality is important for the environment and all of us. Since vehicle emissions are among the main causes of air pollution, emission testing can alert you to problems in your vehicle than can be fix... More