The glare of car headlights could be a risk for heart conditions… As ever-more vehicles use dazzling LED beams

Anyone who drives at night knows the fear of suddenly being blinded by powerful headlights from oncoming traffic; In fact, 90 percent of British drivers complain that modern vehicle lighting is particularly dazzling.

So the news that the government is launching an investigation into blindingly bright headlights this month could come as a welcome relief to many.

But tackling the problem of these lights could do more than just improve road safety, researchers suggest: it could also reduce our risk of conditions such as cardiovascular disease and headaches, especially in middle-aged or older drivers.

The move follows a campaign by the RAC and anti-glare group LightAware. A recent RAC survey of 2,000 motorists found that 85 percent said headlight glare is getting worse.

Official figures show that bright headlights have contributed to an average of 280 collisions on British roads every year since 2013.

In a recent RAC survey of 2,000 motorists, 85 percent said headlight glare is getting worse (Stock Image)

The RAC blames the introduction of more powerful LED lights and the growing popularity of four-wheel drive models and SUVs, which sit higher on the road and have lights that shine directly into the driver’s eyes.

LED lights also make the brain see them brighter than they are, thanks to the perception phenomenon “contrast brightness,” according to a study in the Journal of Passenger Cars – Mechanical Systems.

When drivers were placed in front of equally powerful LED and traditional headlights, the LED group complained that the lights were more dazzling.

The researchers said this is because our brains judge brightness based on the contrast between a light source and the light level surrounding it. (For example, a house lamp may appear barely bright during the day, while at night it lights up the room.)

Because LEDs are small and emit tight beams compared to loosely focused traditional headlights with halogen bulbs, they create a sharper contrast with the darkness around them, making the light appear brighter, the 2005 report said. In addition, modern LED headlights are about two times brighter: 6,000 lumens compared to about 3,000 for halogens, Dr. John Lincoln, a retired LightAware immunologist, told Good Health.

This LED glare can cause stress that can damage our cardiovascular system, according to research from the Karolinska Institute in Sweden.

They found that bright headlights could cause worrying changes even in young, healthy people. In one study of 19 drivers under the age of 40 who were exposed to five sudden bursts of strong light from headlights, one volunteer showed a potentially dangerous increase in blood pressure, while another temporarily developed ventricular extrasystole, a heart rate abnormality associated with heart attacks .

Older and less healthy drivers may be in worse shape; the 1998 report found that drivers in their mid-forties and older who had symptoms of heart disease, such as high blood pressure, were also the most sensitive to sudden glare from headlights and the most likely to have cardiovascular reactions – possibly because the bright lights made them fight or flight response.

Headlights that are too bright can also cause migraines, Dr. Lincoln warns: ‘LED headlights cause visual stress due to the contrast brightness. This can trigger attacks in people who suffer from light-induced migraines, making it difficult to drive safely.”

Such pain is a natural reaction to sudden glare, according to Peter Heilig, professor of ophthalmology at the University of Vienna. ‘Glare sends a warning signal to the brain with the message ‘Stop!’. It is comparable to the pain signal you get when you suddenly overload a joint.’

Dr. Lincoln explains that LED headlights can be particularly painful because “unlike other lights, their intensity decreases more slowly, making these lights blinding over longer distances.”

Glare pain is also amplified by LED wavelengths, which are on the blue end of the light spectrum: this causes more discomfort than comparable light levels in the yellowish spectrum of halogen lamps, according to 2007 research by the US National Highway Traffic Safety Administration. (NHTSA).

This is especially dazzling – and dangerous – for aging eyes. Denise Voon, Clinical Advisor to The College of Optometrists, explains: ‘If you look at bright light and then look away, you can still see the afterimage. In older people, recovery can take considerably longer.’ And LED glare dramatically increases drivers’ recovery times, the NHTSA found.

Over 60, our eyes’ ability to recover from glare at night begins to decline significantly as the light-sensitive rod cells – which help with good vision in low light – become weaker.

In addition, the tiny muscles that control the size of our pupils (and how much light they let in) also become weaker, so they don’t quickly recover from closing tightly when they’re blinded.

This explains why the NHSTA found that older drivers’ eyes took significantly longer to regain sensitivity after exposure to glare – as much as ten seconds. If you drive at 60 miles per hour, that means traveling 268 yards, two and a half football fields, while not being able to see properly.

Add to this the problem of cataracts, where proteins in the lens begin to break down, causing the lens to become cloudy. A 2018 Harvard University study found that volunteers with cataracts who crashed into a bright headlight were much more likely to fail to notice a pedestrian crossing the road in time to avoid him.

LightAware is calling on the government to set realistic safety standards for headlights, including limiting the amount of blue spectrum light.

Meanwhile, campaigners suggest drivers avoid looking directly at approaching vehicles at night; Instead, look about 20 degrees to the right, toward the white line on the right side of the road, and then use peripheral vision to look ahead at those times. Or buy night driving glasses, which have a coating that filters blue light.

And visit your optometrist regularly, says Denise Voon. ‘Things like macular degeneration can make the problem of headlight glare a lot worse. Prescription glasses can make a big difference.’