Back to all

See the Light (Automatic High Beam Dimmers)

April 9, 2023

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 Lake In The Hills
59 West Acorn Lane
Lake In The Hills, Illinois 60156
847-854-9850

More articles from Tuffy Lake in the Hills

A Bright Spark (Ignition Coil Replacement)

January 26, 2025

Ever wonder how your vehicles engine is able to take the 12-volts from its battery and ramp that up to as high as the tens of thousands of volts it takes to fire its spark plugs? The secret is something called an ignition coil. Most newer vehicles have an ignition coil at each cylinder, but olde... More

No Fueling Around (Fuel Filter Replacement)

January 19, 2025

A driver called in to the shop the other day saying his European sports sedan had an odd problem. He was driving when his car started to slow down. Applying more throttle didn't help. He pulled over to the side of the road, shut the engine off and waited a few minutes before starting it up aga... More

PCV Valve: What Is It?

January 12, 2025

Most Lake In The Hills drivers know something about preventive maintenance on a vehicle. We know we should routinely replace the oil and wiper blades and other fluids. But have you heard of a PCV valve ? This little car part needs to be replaced regularly or it can cause some serious problems in ... More