Back to all

See the Light (Automatic High Beam Dimmers)

December 20, 2020

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. 

Tuffy Tire & Auto Service Batavia
301 S. Randall Rd
Batavia, Illinois 60510
630-879-9941

More articles from Tuffy Batavia

Motor Oil?The Synthetic Advantage (Synthetic oil vs Conventional)

March 15, 2026

Youve probably already heard that regular oil changes are extremely important for the health of your vehicles engine. Thats sound advice. But what you might not know is when it comes to motor oil, the real thing may not be the best thing for your engine. There are different types of motor oil: ... More

Before You Buy a Used Vehicle (Car Inspection before Buying a Used Vehicle)

March 8, 2026

Before You Buy a Used Vehicle (Car Inspection before Buying a Used Vehicle) Perhaps this sounds familiar. Your vehicle seems like its been around forever, and youve decided its time to move on. But when you check the price of new vehicles, the sky-high price tags have you considering a nice, pre... More

The New Blade in Town

March 1, 2026

If your windshield wipers are streaking and chattering when you turn them on in the rain or snow, it's time for a little "blade renewal." And when it comes to new wiper blades, there are some new designs that are worth a look. One of the latest is called the beam blade. It's different than conve... More