Who Taught You to Drive?

Headlights pose glaring issue for older motorists

Modern headlamps are brighter than 20 years ago, but are designed to shine away from oncoming drivers, experts say. Modern headlamps are brighter than 20 years ago, but are designed to shine away from oncoming drivers, experts say. (GLOBE FILE)
By Peter DeMarco
Globe Correspondent / February 2, 2012
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Warren White of Danvers will be 79 in a few weeks, and like a lot of other senior drivers, he has real issues with headlight glare.

“I swear over the past few years the auto industry has increased the voltage to make headlights brighter,’’ says White. “They’re better for the driver but not for people in oncoming cars. There are times I pass another driver and I can’t see anything. I’m blinded and I’m afraid I’ll hit something.’’

After hearing White’s complaint I figured he was talking about Xenon headlights, those stunningly bright, bluish-tinged lamps usually found on higher-end cars. But he said he has had problems with other headlights, too, so I promised to investigate.

Are car headlights brighter than ever? What causes bad glare? And why do older drivers have such problems with oncoming lights? We try to answer these questions in today’s column.

Way brighter

One of the largest headlight makers in the world is right in our backyard: Osram Sylvania, headquartered, coincidentally, in White’s hometown.

According to Greg Bibbo, product marketing manager for Sylvania’s automotive lighting division, the average halogen headlight is indeed 40 to 70 percent brighter today than 20 years ago. But that’s nothing compared with those bluish-tinged, high-intensity discharge lights, which are more than 400 percent brighter than headlights from the early 1990s.

Technically speaking, a headlamp’s light is measured in lumens. Old headlights gave off 700 lumens of light; new headlights give off 1,000 to 1,200 lumens; high-intensity discharge lights (the term Xenon is really a misnomer, Bibbo said) give off 3,000 lumens.

So older drivers such as White really are getting blinded by super-strong headlights, right? Not exactly, Bibbo said.

“These numbers shouldn’t evoke the response that because headlights are brighter, there is more glare,’’ he said. “Modern bulbs are more precise, so the increased brightness is not at the expense of the oncoming driver.’’

Manufacturers must design lights according to strict standards imposed by the National Highway Traffic Safety Administration, which include everything from dictating the exact placement of a filament within a bulb to the design pattern of a light’s hard plastic cover, known as its reflector, Bibbo said. Reducing glare is a primary requirement.

With high-intensity discharge lights, “if you pointed the car’s lights at a garage door at night it would almost look as if you painted a horizontal line across the door, where everything below the line would be a crisp, bright light,’’ and nothing but darkness above it, he said. “Stray light above the horizon is what would be oncoming glare.’’

Still not foolproof

No manufacturer can guarantee a glare-free headlight, however. Everything from improperly inflated tires to a fender-bender to a good rattling from a pothole can knock headlights out of alignment, said Roger Montbleau, longtime owner of Lowell Automatic Transmission. Even a small tilt can change a beam’s trajectory by several feet, he said.

Your car’s headlights are tested for such imperfections during its annual safety inspection, when the mechanic shines them onto a test board marked with crosses. Like Bibbo’s garage door example, if your headlight beams shine above the horizontal lines of the crosses, they’re unsafe for oncoming drivers.

“It can be off a little, but basically the light has got to set up in the crosshairs or you’ll fail the inspection and you have to get them adjusted,’’ said Montbleau. Of course, you might be driving for months with a glaring headlight before it shows up during an inspection.

Though all vehicle headlights must meet the government’s standards, a tall SUV or high-riding pickup truck’s lights might cause some glare for those driving much smaller vehicles, Bibbo said. Likewise, the contour of a road could send your headlights upward, creating some glare. “Even with a perfectly aimed light, when I’m coming over the crest of a hill, they’re going to be aimed higher,” he said.

Illegal or improperly installed after-market headlights are another source of dangerous glare.

“I can pick out the inappropriate conversion kits very easily,’’ Bibbo said. “If you see a car that’s 20 years old with bluish lights and a glare that makes it look like they’re driving with their high beams on, chances are it’s not legal. It’s frustrating for us because we make upgrade kits that are legal and safe, but they are more expensive.’’

Finally, there’s no cure for drivers who actually do leave their high beams on.

“The whole idea of a horizontal cutoff line is nonexistent on a high beam,’’ Bibbo said. “They’re brighter and not focused and designed to be shooting light as far down the road as far as they can.’’ Manufacturers, he said, “don’t design them worrying about glare in another driver’s eyes, because you’re not supposed to drive with high beams on when you see an oncoming car.’’

Tough on aging eyes

Beyond all the common factors that cause glare, drivers such as Warren White must add one more: age.

“To an older driver, lights are brighter because their eyes are more sensitive than someone in their 20s. It’s a common complaint in the industry,’’ said Bibbo. “An older person’s eyes don’t adapt as quickly. When an older person sees headlights coming on, it’s harder for them to recover than a younger driver.’’

Dr. Scott Greenstein, attending ophthalmologist at Massachusetts Eye and Ear Infirmary and a Harvard Medical School faculty member, said older drivers have a higher incidence of cataracts, glaucoma, and weakened retinas, in a condition known as macular degeneration, all of which lead to more problems driving at night.

“In general, as people age the lens loses some of its clarity that’s there when we’re kids,’’ he said. “It’s more of an effort to drive at night because there’s less illumination, more glare. Many people, particularly older people, are bothered by oncoming lights.’’

Unfortunately, aside from wearing sunglasses, which reduce road glare but may not be a good option at night, there’s not much older drivers can do. A spokesman for the National Highway Traffic Safety Administration told me the federal government is studying ways to reduce headlight glare, particularly for older drivers. But it’s anyone’s guess as to where that will lead.

Still, Montbleau, who is also president of the New England Service Station & Automotive Repair Association, offered one encouraging thought. Modern headlights greatly increase visibility for the vehicle’s driver, so if you can’t beat them, at least join them.

“Members of my service association say that seniors are requesting their garages install brighter lights in their own cars,’’ he said. “Seniors need all the light they can have to see at night.’’

Peter DeMarco can be reached at

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