Anyone who drives at night will know the terror of being suddenly blinded by powerful headlights approaching from the opposite direction; In fact, 90 per cent of UK drivers complain that modern vehicle lights are particularly blinding.
So the news that the Government is launching a review this month of blindingly bright headlights may bring welcome relief to many.
But addressing these lights could do more than improve road safety, researchers suggest: It could also reduce our risk of diseases such as cardiovascular disease and headaches, particularly in middle-aged and older drivers.
The move follows a campaign by the RAC and anti-glare group LightAware. In a recent RAC survey of 2,000 drivers, 85 per cent said headlight glare is getting worse.
Official figures show that bright headlights were a contributing factor to an average of 280 collisions on UK roads each year since 2013.
The government is addressing the issue of bright headlights that could help reduce the risk of diseases such as cardiovascular disease and headaches, especially in middle-aged and older drivers.
In a recent RAC survey of 2,000 drivers, 85 per cent said headlight glare is getting worse (File Image)
The RAC blames the introduction of more powerful LED lights and the growing popularity of SUV and four-wheel drive models, which sit higher up the road with lights shining directly into the driver’s eyes.
LED lamps also trick the brain into seeing them brighter than they are, thanks to the perceptual phenomenon of “contrast brightness,” according to a study published 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 blinding.
The researchers said this is because our brains evaluate brightness based on the contrast between a light source and the level of light around it. (For example, a house lamp barely seems to shine during the day, while at night it illuminates the room.)
Because LEDs are small and send out narrow-edged beams of light compared to traditional headlights with narrowly focused halogen bulbs, they create a starker contrast with the darkness around them, making the light appear brighter, depending on the vehicle. report from 2005. Additionally, modern LED headlights are about twice as bright: 6,000 lumens compared to about 3,000 for halogens, Dr. John Lincoln, a retired LightAware immunologist, told Good Health.
This glare from LEDs can cause stress that can damage our cardiovascular system, according to research from the Karolinska Institute in Sweden.
They found that glaring headlights could cause worrying changes even in young, healthy people. In one study, involving 19 drivers under the age of 40 who were subjected to five sudden bursts of intense headlight glare, one volunteer showed a potentially dangerous increase in blood pressure, while another temporarily developed ventricular extrasystole, an abnormality. of the heartbeat associated with heart attacks.
Older, less healthy drivers may have worse outcomes; The 1998 report found that drivers ages 40 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 show cardiovascular reactions, possibly because bright lights They intensified their pain. fight or flight response.
Too bright headlights can also cause migraines, warns Dr Lincoln: ‘LED headlights cause visual stress due to contrast brightness. This can cause attacks in people who suffer from light-induced migraines, making safe driving difficult.’
According to Peter Heilig, professor of ophthalmology at the University of Vienna, this pain is a natural response to sudden glare. ‘Glare sends a warning signal to the brain that says ‘Stop!’ It is comparable to the pain signal received when a joint is suddenly overloaded.’
Dr. Lincoln explains that LED headlights can be particularly painful because, “unlike other lights, the intensity drops more slowly, making these lights blinding at longer distances.”
Pain from glare is also intensified by LED wavelengths, which are at the blue end of the light spectrum: this causes more discomfort than comparable levels of light in the yellowish spectrum from halogen bulbs, according to research of 2007 from the US National Highway Traffic Safety Administration (NHTSA).
This is particularly glaring (and dangerous) for aging eyes. Denise Voon, clinical advisor at the College of Optometrists, explains: ‘When you look at a bright light and then look away, you still see the afterimage. For older people, recovery can take much longer.’ And LED glare causes drivers’ recovery times to increase dramatically, the NHTSA found.
Starting at age 60, our eyes’ ability to recover from nighttime glare begins to decline significantly as the light-sensitive rods, which help with good vision in low-light conditions, weaken.
Additionally, the tiny muscles that control the size of our pupils (and the amount of light they let in) also weaken, so they don’t quickly recover by squeezing shut when dazzled.
This explains why NHSTA found that older drivers’ eyes took much longer to regain sensitivity after being exposed to glare: up to ten seconds. Driving at 100 km/h means traveling 268 meters, two and a half football fields, without being able to see well.
Added to this is the problem of cataracts, when the proteins in the lens begin to break down, causing the lens to cloud. A 2018 Harvard University study found that volunteers with cataracts who drove toward a glaring headlight were much more likely to fail to spot a pedestrian crossing the street in time to avoid it.
LightAware is calling on the Government to set realistic safety standards for headlights, including limiting the amount of blue spectrum light.
Meanwhile, activists suggest that drivers avoid looking directly at oncoming vehicles at night; Instead, look about 20 degrees to the right, toward the white line on the right side of the road, then use your peripheral vision to look ahead at those times. Or buy night driving glasses, which have a coating that filters out blue light.
And see your optometrist regularly, says Denise Voon. ‘Things like macular degeneration can make the headlight glare problem much worse. “Prescription glasses can make a big difference.”