The Sunday Times (Jan 11th 2025) - Why have car headlights got so bright — and what are the dangers?
Dazzling headlights are responsible for at least 280 collisions a year, and a trade in illegal super-bright LED upgrades is thriving.
What has been described as an “arms race” in LED headlights has resulted in them getting steadily brighter.
There’s a moment that sticks in Tim Riley’s mind. “It was pitch dark, on a narrow two-way road. A vehicle came around the corner towards us, from a slight rise in the hill … and the lights just came at us. They were blinding. You couldn’t see for several seconds.
“My partner was panicking, and I just had to try and remember what the road looked like and slow down. It was frightening.”
It’s a situation most drivers will recognise.
For Riley, 50, such encounters on the dark and winding roads around his home in the Lake District have become so common that he tries not to drive in darkness at all — but the problem is nationwide. A survey of 2,000 drivers by the RAC found nine in ten think at least some lights are too bright: of those, three quarters say they are regularly dazzled and 85 per cent say the problem is getting worse.
Many people think they know the reason, too: the increasing prevalence and power of LED (light-emitting diode) headlights. “There’s almost an arms race in car headlights,” said John Lincoln of the campaign group LightAware, of which Riley is also a member. “The car manufacturers have increased the intensity of the light.”
Traditional halogen lights typically emit about 1,000 lumens, a measure of their perceived brightness. “The LEDs on new cars are much more powerful — they often don’t publish that information, but we think for many it’s around 6,000 lumens. And now people in older cars are upgrading their halogen lights with ridiculously bright LEDs.”
Such installations are often illegal. LED lights are not certified for use in headlight units built for halogens, and The Highway Code says that headlights must not dazzle other road users.
But the “aftermarket” in LED bulbs is thriving, and many are promoted specifically for fitting in older cars not designed for them. Traders on Amazon offer bulbs with outputs of up to 35,000 lumens, boasting they “illuminate the road like never before”. What isn’t made quite so clear is that, in the process, they may temporarily blind other road users.
The sheer power of LEDs isn’t the only factor in play. “They give off a higher colour temperature compared to the old-style bulbs,” said Paramdeep Bilkhu, clinical adviser at the College of Optometrists. “They’re whiter, closer to daylight. If you’re in the car using them, that improves visibility; but they’re more likely to dazzle oncoming drivers. Added to that, there’s the position on the car. With more SUVs on the road, the lights tend to be higher up than smaller vehicles — so they can shine directly into the eyes of the oncoming driver.
“It’s much worse at night, because your retinal cells have undergone dark adaptation: they’ve become more sensitive to enable you to see in darker conditions. If you shine a bright light source on someone who is dark-adapted, it’s going to dazzle them.”
Bilkhu said there is currently insufficient evidence to categorically show that brighter lights can harm the eye — but in surveys, drivers say the headlights can leave them blinded for as much as six seconds, enough to travel about 180 yards at 60mph.
Part of the problem may lie in the design of modern LED headlights. While traditional incandescent bulbs emit light in all directions, which is then reflected forwards, many new headlights use a combination of reflectors and lenses to produce a narrower, more focused beam. If this beam shines directly in the eyes of other road users — whether through faulty alignment, or when an oncoming car crests a hill or mounts a speed bump — the intensity of light can be shocking.
The motor industry points out that headlights must meet international standards, and it is an offence to fit an unapproved light source. That doesn’t seem to be stopping some owners.
The effect is most acute for older drivers — as the lens of the eye clouds with age, increasing the perception of glare — and for those in rural areas with no street lighting, which makes the contrast with bright headlights more dazzling. The result can be, effectively, a night-time curfew.
“I have good vision but I just can’t drive at night any more, because these lights completely blind me,” said Gill Crane, 70. “We live in the middle of nowhere in Somerset, and if you want to go out after dark you have to drive. So after four o’clock in the afternoon, that’s it, I’m stuck.
“I question why they make them so bright — is there any real benefit? You need to be able to stop in a distance you can see, don’t you, not in three miles? They’re more likely to cause an accident than prevent one. They’re crazy.”
Dazzling headlights are recorded as a factor in about 280 collisions a year, according to the Department for Transport’s figures, though campaigners say that the true figure may be much higher.
The public disquiet is certainly growing. “Few issues we deal with have triggered quite as much of a reaction among drivers as the brightness of headlights,” said Rod Dennis of the RAC. “It’s clear that, for a proportion of the driving public, glare affects them profoundly on the roads at night.”
That reaction has forced the government into action: a study from the Transport Research Laboratory (TRL), commissioned by the Conservative administration and continued by Labour, is gathering data on the measurable effects of brighter headlights.
“We’ll rig up an ordinary car and equip it with instrumentation in the driver’s seat to capture the experience of light from the driver’s perspective,” said Shaun Helman, the project’s chief scientist. “It will be driven on different routes, in all weathers and all times of day.”
Initial results are expected in April, but they are “unlikely to provide all the answers”, said TRL, and more research may be needed. A change in regulation seems to be far off — too far, perhaps, for even the most powerful headlight to see.
For now, that leaves drivers such as Crane and Riley stranded. “People say anti-glare screens and glasses help a bit, and there’s advice to look at the kerb so you know where you are in the road — but that hardly tallies with having full awareness of the road around you, does it?” said Riley. “And we shouldn’t have to find workarounds anyway. The levels of brightness are just way above what the human eye should be exposed to. I honestly believe these headlights aren’t safe on the roads.”
https://www.thetimes.com/uk/transport/a ... -ft7twjgxg
