Back to all

See the Light (Automatic High Beam Dimmers)

May 16, 2021

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 Fort Wayne - Dupont Rd.
1910 W. Dupont Rd.
Fort Wayne, IN 46818
260.489.4800

More articles from Tuffy Fort Wayne (Dupont Rd.)

In the Red (Why a Vehicle Overheats)

October 12, 2025

Heat is one thing that can damage a vehicle, especially if a problem isnt taken care of soon. Be on the lookout for signs that its getting too hot in some parts of your vehicle, starting with the most obvious one: the heat gauge/warning light on your instrument panel. When you see that heat gaug... More

Knowledge is Power (Battery Testing)

October 5, 2025

Its likely happened to you once or twice. You head to your vehicle, open the door, turn the key and lo and behold, your battery is dead. Now youre stranded, may have to get a jump or a tow, and youll definitely be late for wherever you were headed. While your vehicle may sometimes give you warni... More

See the Light (Bulb Replacement)

September 28, 2025

When you notice one of your headlights has gone out, its important for the safe operation of your vehicle to get it changed and working again. Not only is replacing a headlight important for your ability to see in the dark, but its also vital that it be lighting your way and aimed correctly so o... More