History of the Sealed Beam Headlight

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One of the most identifiable features of classic American cars are their headlights. Up until the mid-1980s, almost all vehicles sold in the United States had either round or square glass lights. Manufacturers played around with headlight arrangement and orientation, but they were all fundamentally the same.

These particular kinds of lamps are called sealed beam headlights, and there’s a reason why they were so common. Here’s what happened to sealed beam headlights, and why they went away so suddenly.

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Early Headlights—Rules? What are Those?

In the 1930s, electric headlights were barely 20 years old. Before 1910, many cars still used carbide or kerosene lamps. These flame-based lights were only useful for alerting others to the presence of a car—not illuminating the road.


By the time that the Ford Model T standardized electric headlamps, drivers could finally expect to see the road as they drove along. Plus, their cars exploded less. At first, manufacturers experimented with a wide range of bulb-based lights. Even with the improvements, early electric headlights still weren’t very useful, and rural areas (where most people lived at the time) had minimal street lighting.

But in 1939, General Electric had a bright idea. They invented a sealed headlight complete with a reflector, durable glass lens, and a tungsten filament⁠—which was much brighter than existing lights. It didn’t take long for automakers (and the Federal Government) to notice.

1940 - Federal Safety Standards


The Feds passed new standards soon after the introduction of the sealed beam headlight. In 1940, they implemented a rule that required all new automobiles to come equipped with two 7” round sealed beam headlights.

1957 - The Government and Classic Car Design

The law remained mostly unchanged for years. And as you’ll notice, so did car headlights. That is, until 1957. If you’re tuned into classic cars, you’ll note an exciting change in car design around that time.


In 1957, the Federal Government allowed automakers to choose between two 7” round sealed beam headlights and four 5 3/4” round sealed beam headlights. This 1958 Cadillac is a notable example of the new design.

1961 - Europe Moves On

By the mid-1960s, cars looked very different on the other side of the lake. Engineers in Europe and Japan began ‘doing the engineering’ and came up with advanced and attractive alternatives to sealed beam headlights.


U.S. import standards began to seem a bit ridiculous. Foreign car companies had to produce two versions of the same car⁠—one for Europe and one for America. In 1961, Citroën introduced rectangular headlights on the Ami 6. It would take nearly 15 years for the United States to catch up.

1975 - Squares

Notice anything unusual about late 1970s car design? Everything suddenly got so… square and boxy. If you noticed a change, you’re on the right track—something big happened in 1975.


By 1975, automakers had enough of the Federal Government and their refusal to budge on headlight shape. They pushed, the Feds caved, and the rectangular sealed beam headlight was finally permitted in the United States. But the excitement was short-lived, as the next significant change in American car headlight design was just around the corner.

1983 - Ford Changes the Game

Ford was a little more frustrated with headlight laws than most. In 1981, they petitioned the Federal Government to allow variable-sized headlights with replaceable bulbs and hard plastic (polycarbonate) lenses. Due to the not-so-recent adoption of the brighter halogen bulb, such headlights could safely illuminate the road. The Feds agreed in 1983—and Ford had a field day.


Just a few short years later, dozens of vehicles on American roads had proprietary headlights. The 1984 Lincoln Mark VII, the Lamborghini Countach, and the 1987 Ford F-Series come to mind, along with the 1985 Ford Granada pictured above.

Sealed Beam Headlights Today

Sealed beam headlights may be off the radar, but they’re not dead. Even though better and brighter technology exists, there’s still a huge market for sealed beam lights.


Walmart carries them. New utility vehicles (such as fire and delivery trucks) still use them. Classic car enthusiasts like us burn them out on a regular basis. Sealed beam lights are strong, reliable, and inexpensive to replace. So now you know the history of the sealed beam headlight, and why American car design seemed to change dramatically in the 1980s and 1990s. Next time you’re in an auto parts store, remember to thank the government for making your pre-1990s headlights easy to find.