Why are modern car headlights so bright? How to prevent dazzle

Why are modern cars’ headlights so bright? We explain what’s causing more drivers to be dazzled at night and how to prevent it

Are car headlights getting brighter? Ask around, and you’ll find it’s a common grumble among anyone that drives, especially those that frequently take to the road first thing in the morning or at night.

They’ll tell you that on an unlit road, especially one with crests or undulations, oncoming traffic can leave them feeling as if they can’t see.

During the winter months, the problem is exacerbated. Fewer daylight hours mean cars spend more time with their lights on. And the latest technology on modern cars has introduced superior lighting power to even the average family car.

While that’s great for any driver of a car with powerful lights, it’s not so safe for drivers of oncoming vehicles. They can find themselves blinded by the brilliant light from the latest systems.

Is there anything dazzled drivers can do? And will headlights continue to get brighter?

What’s the problem?

It’s a fact that car headlights are getting brighter. The motor industry is continually boasting about how it has improved lighting performance, to keep drivers safe. Meanwhile, eye specialists say the downside is that this actually impairs the vision of increasing numbers of drivers in oncoming traffic.

At the same time, as drivers age the eye’s lens and cornea effectively become misty, and as bright light in shone through them, drivers suffer something called ‘disability glare’. Studies have shown it can take up to 10 seconds to recover from the phenomenon.

According to police data, accident investigators report ‘dazzling headlamps’ as an influence in 10 fatal crashes, nearly 70 serious accidents and more than 250 other accidents.

Bicycle lights can be just as dazzling

Given the improved performance of bicycle lights, they can be just as dazzling for oncoming traffic. Especially if the rider hasn’t correctly positioned the light to ensure the light beam isn’t in the direct eyeline of oncoming drivers.

Is there a quick fix for drivers?

Happily, there is. Professor John Marshall, of University College London, says anyone can buy and use special clear glasses, even if they don’t need prescription lenses. These have a coating on the lens to absorb ultra violet light and prevent glare when driving at night. They are relatively inexpensive, from £10, and any optician will be able to advise what best suits a driver’s needs.

Other preventative measures

If your car’s windscreen is dirty, either on the inside or outside, the dirt will cause light to refract, making it harder to see where you’re going. It’s also important to ensure your car’s headlights are correctly adjusted and the bulbs aren’t aged with use. And don’t forget to take an eye test regularly – at least every two years, according to optometrists.

What are car makers doing?

Ford is going to great lengths to make its latest family cars safer for owners and other drivers alike. Its new Glare-Free Highbeam adjusts the headlight beam angle and intensity to one of seven settings according to speed, ambient light, steering angle, distance to the vehicle in front and windscreen wiper activation. Find out more about it, in our earlier blog post. Other mainstream car makers are developing similar systems. However, as anyone who has used them will know, they aren’t foolproof.

From halogen lights to Xenon systems

Why are modern cars’ headlights so bright? We explain what’s causing more drivers to be dazzled at night and how to prevent it

Traditional halogen bulbs made way for brighter Xenon, or high intensity discharge (HID) lights in the early ‘90s. BMW first fitted the system to its 7 Series flagship. It was widely praised by users for the brightness of the light and associated reduction in driver fatigue. The bulbs also lasted longer, for around 2000 hours.


Why are modern cars’ headlights so bright? We explain what’s causing more drivers to be dazzled at night and how to prevent it

First fitted to the Audi A8 luxury saloon in 2004, engineers and designers alike prefer to use light-emitting diodes (LEDs) when making modern cars. That’s because they use less power than Xenon units, give more freedom for styling the body parts, as they’re so compact, and the light produced is bright.

There are other advantages. The light can be manipulated, such as when adjusting the pattern of the full beam to allow for oncoming traffic or pedestrians. And they are claimed to last for comfortably more than 5000 hours.

The latest headlight tech: matrix laser lights

If you thought LEDs were bright, think again. Audi was the first car company to fit laser lights to a car, in 2014. The technology sounds like it belongs in a Star Wars movie. But high-intensity laser diodes are fitted to the Audi R8 sports car and light the road ahead when the driver selects the main (full) beam pattern.

The laser system is claimed to offer twice the range of even the brightest LED. Its laser diodes create a bright blue light that has to be filtered by phosphor converters to make it white and harmless to the human eye.

In the future, Audi engineers hope to combine laser lights with driver aids to help pick out pedestrians, project graphics – to help indicate the width of the car – or pick out road signs.

67 comments on “Why are modern car headlights so bright? How to prevent dazzle

  1. John Harper January 23, 2018 6:20 pm

    If accidents have been caused by these ridiculous headlights I would have thought there would be a case for taking the vehicle manufacturer to court! Make your voice known Green Flag and get the vehicle manufacturers to re-call these dangerous models to change the headlights.

  2. Gladys Mead February 6, 2018 4:25 pm

    Thanks for the information

  3. tim February 6, 2018 5:53 pm

    I find a lot of cars that are dazzling are foreign registered , this is because their headlights are set wrongly for driving on the left, they are not using beam deflectors as we have to when we drive abroad, if we drive without them abroad we face a fine , but this does not seem to be enforced here in the uk

    • Victor Biush February 16, 2018 4:47 pm

      I agree entirely. Isn’t this something the EU shjpould be sorting pout?

      • Barrie Lindsey February 19, 2018 11:16 pm

        Why put this on the EU? We do not need nurse maids, we just need action from our Minister of Transport and Parliament. They could make it law that all headlights should sense oncoming lights and dip automatically.

  4. Derek Reed February 6, 2018 7:23 pm

    Surely it is illegal to dazzle other drivers, so vehicle manufacturers must take the blame.

    • DAVID CORY February 14, 2018 3:49 pm

      Drive often at night time, The car or van behind,even on dipped beam floods my car interior and reflects in my wing mirrors ,I have been made to slow down and wave the vehicle past,surely again these lights are breaking the law. My MOT tester would not pass them.

      • chris kilkenny February 20, 2018 8:30 am

        a lot of mot stations are passing cars on there lights without checking beam alignment also passing cars without number plate lights which is a legal requirement and you are right about bright lamps I thought uk law states maximum bulb brightness of no more than 100w

  5. Alan eastman February 7, 2018 9:36 am

    Dear GreenFlag,
    Thank you for all your interesting information and advice. A problem I find at night is being able to decide if an oncoming car has an indicator flashing. Most cars these days have their front indicators included in the headlamp cluster. This I feel is bad as the indicator light is drowned out by the brightness of modern headlamps. Therefore I think indicators should be separate from headlamp clusters and on the extreme sides of the vehicle and not inboard to some degree, as so many are. It’s also worth remembering that at least one in ten males are to some degree colour blind, as am I. Red/green/brown is the most common

    • PAUL JARVIS February 13, 2018 10:00 am

      Well done Alan, I couldn’t agree more. Many front indicator lamps are invisible when the headlamps or Daylight Running lamps are on – rubbish design. This is both dangerous and causes unnecessary congestion/fuel waste/emissions waiting for vehicles to pass when in fact it’s turning off etc. What are the DVSA there for? It’s about time they started earning their money.

      • Chris W February 14, 2018 1:32 pm

        I totally agree with everything that is said. I would also like to mention that brake lights are also getting brighter and drivers still sit at traffic lights with their foot on the brakes instead of applying the handbrake. This can cause an image in the eye when the brake is finally released

        • Brian Sweeting February 17, 2018 4:54 pm

          In contravention of the Highway Code. Also badly taught by driving schools.

    • DAVID CORY February 14, 2018 3:43 pm

      Totally agree stupid design ,surely these cars would fail the MOT. Not only causes confusion at night time, day time driving lights are brighter than the indicators.Been caught out a number of times on mini-round abouts.

  6. Eileen Long February 7, 2018 3:41 pm

    I wear glasses with anti glare lenses but still have problems with car headlights and even more so when it is raining. What is the answer to that problem?

    • Jeff March 2, 2018 1:09 pm

      I try to drive behind another car so he get’s most of the problem with the oncoming traffic!

  7. D Temple February 8, 2018 9:39 am

    Recall of all cars fitted with these driver dangerous lights ! If these drivers of cars with these lights cannot see at night , they should not be driving at night !

  8. Ian Herridge February 8, 2018 11:13 am

    I think the introduction of dipped headlights in towns and cities was a mistake. So much light, especially on wet days, washes out any detail around the vehicles. They should have scrapped the 5 watt side light and increased it to 21 watt. Also, people replacing bulbs and not fitting them properly.

  9. Sue February 8, 2018 1:51 pm

    Interesting information. I am in my 60’s and I don’t like driving in the dark now because of oncoming dazzling headlights. I wear glasses with anti glare for driving which helps a bit but I still find I am being dazzled by these bright headlights and when it is wet it is much worse. I feel it distorts things when wet and I cannot judge distances as I should. Unfortunately it is impossible not to commute when dark.

  10. Freda Gibbs February 8, 2018 8:19 pm

    I agree with Alan Eastman’s comment, even in daylight on a wet dull day if drivers have their lights on it’s hard to make out in some models if an indicator is being used.

  11. Isobel February 9, 2018 9:27 am

    I have long thought that the new bright white lights are dangerous – both on cars and bicycles. Bright red cycle lights are equally dazzling. The flashing/pulsating setting on cycle lights just compounds the issue further. It’s impossible to see beyond these lights, which makes night driving increasingly hazardous. The sooner these types of lights are outlawed and replaced the better.

  12. Carol Byrne February 9, 2018 9:45 am

    What ever happened to the “Don’t Dazzle Dip Your Headlights” campaign?? This should be brought back. Just by ensuring your headlights are set to “dip” can stop the glare from going straight into the eyes of drivers on the opposite side of the road.

    I have never seen a cyclist who’s lights have been adjusted so they don’t dazzle cars/bikes/pedestrians coming in the opposite direction.

    Rather than the lengthy and expensive way of taking manufacturers to court simply bring back an updated “Don’t Dazz/Dip” campaign??

  13. A. Simpson February 9, 2018 11:38 am

    Thanks for the info that highlights a common experience, this is set to get worse even for a pedestrian that may be “picked out by approaching vehicles”. The best approach is surely the liberal use of the most efficient reflective materials to inform the driver of a blinding situation. Even if the driver is blinded by their own lights.

  14. Linda Taylor February 9, 2018 2:24 pm

    I do agree that modern headlights are a hazard can motoring organisations like yourself please put pressure on manufacturers to reconsider their use or at least put some effort into making them safer? I also agree with the comment about including indicator lights in the cluster and them being invisible by comparison. I have had a near miss because of this. Style shouldnt over ride safety considerations.

  15. Betty Brunner February 9, 2018 4:34 pm

    Thank you for the info

  16. Robert Henry February 9, 2018 4:43 pm

    Good points well made, john and Alan

  17. Margaret Berry February 9, 2018 7:49 pm

    Thanks for all the information, which is so informative.

  18. Colin Brothers February 9, 2018 10:23 pm

    Having all these fancy lights is all well and good, but there are an increasing number of drivers on the road with both a headlight and sidelight not working. Highly dangerous when coming up behind me but far worse coming toward me as it appears to be a motorbike. I wonder if drivers actually check their lights reflection in the bodywork of the vehicle in front.
    I have a pair of glasses for driving at night and find them very useful especially in the wet when these high powered lights reflect and dazzle.

  19. Anne Williams February 10, 2018 9:43 am

    Another problem i find is when one of these monsters is behind you and the glare is lighting up your car and reflecting off your mirrors. A passing car on the other side of the road is a matter of seconds, one behind you can be there for miles.

  20. Mike Wheatlander February 10, 2018 10:19 am

    As in many areas of road traffic regulation, enforcment has been scaled back over the years, and many vehicles have badly adjusted headlights, or have been left on continental settings. Also, cars are quite often parked, albeit for short periods when un/loading, facing oncoming traffic with headlights still switched on. It only takes a second to dazzle.

  21. Rod Giles February 10, 2018 3:15 pm

    I think a lot of motorist are fitting illegal road lights, some of which are 100 watts, way above the legal 55 watts.

  22. Alan worthington February 10, 2018 8:05 pm

    Your interior mirror will clip at an angle to stop being dazzled from cars behind

    • Stewart Lowis February 16, 2018 6:49 pm

      This doesn’t always work, if the vehicle behind is large enough in comparison to your own you can still be dazzled in your interior mirror even with it adjusted

  23. benjamyn dee February 10, 2018 11:40 pm

    I AMA amazed st t(e number of cars, some fairly new, with only one working headlamp. Rear fog warning lights on when the road is wet but not foggy are, in my view, worse than front bright lights as these pass I. A moment whereas it is often difficult to pass someone on many of our roads.

  24. Andy B February 11, 2018 11:24 am

    Agree totally with the comments above This has been a menace for some time now. WHY are manufacturers allowed to produce cars with VERY bright & dazzling headlights and obscurely positioned indicators? As a driver of 35+ years, I instinctively look at the outer “corners” of a vehicle for the indicators. Legislation should dictate maximum brightness levels for headlamps and that manufacturers position the indicators on the outer corners of light clusters. I have even been dazzled by daylight running lights on some cars – which are often so bright, drivers forget to put their headlights on when it goes dark!!!! Ridiculous.

  25. Rita Stalley February 11, 2018 6:21 pm

    Thanks although l drive much at night, l will ask about glasses that help

  26. Karen February 11, 2018 9:01 pm

    My Husband and I have been complaining about these bright headlights for some time, my Husbands pet hate is when drivers leave them on when they are parked up – especially on the wrong side of the road.
    They are so dangerous and even if they were the cause of one fatal accident they should be banned

  27. Peter Smith February 12, 2018 1:23 pm

    If optometrists can put a clear anti glare coating on glasses, then why do windscreen manufactures as it is relatively cheap, not use the same technology? or the motor industry insist that the do? If this happened there would not be a problem with high brightness lighting.

  28. Chris February 12, 2018 2:50 pm

    In addition to very bright head lights, why do so many drivers also use their fog lights when there is no fog. Don’t they realise how dazzling they can be to oncoming traffic ?

    • George Moorfield February 20, 2018 10:20 pm

      Chris, drivers that leave their fog lights on, be they front or rear, when not in foggy conditions are breaking the law.

  29. Malc February 12, 2018 5:23 pm

    I find the headlights on Range Rover models dazzling, especially from behind on the motorway. They seem to be mounted very high on the front of the vehicle.

  30. Baz February 12, 2018 5:23 pm

    The law states that the legal wattage of a conventional bulb should be no more than 55w these new lights are the equivalent to 150w or more and produce an almost white light but are rated as lower wattage just more efficient.
    They should be illegal but the loophole exists and will be exploited just as screens are being used in the front of cars instead of normal controls.

  31. David Field February 12, 2018 6:33 pm

    I see no reason why in a city, which is well lit, why one has to use these Qh lights, do the owners of these vehicles have bad eye sight, in that case, that should not be driving, or is it by their nature to show off, and annoy other drivers with their blinding lights. In respect of the manufactures of these lights, what were they were thinking of, did they research the effect of these lights on other drivers. I drive a 1991 Volkswagen Golf Driver II, my lights do not blind any other driver, they are sympathetic to other drivers on the road, and are suitable for any weather and road conditions.

  32. Kate Stevens February 12, 2018 7:28 pm

    Yes i am increasingly finding that car head lights are more and more dazzling. I thought it was just me and that it was as a result of the aging process! While getting older may not help I have found it interesting to know that car manufacturers are making cars with so called improved head light systems for the driver. This does not help the driver that is dazzled by these lights and it has decreased my confidence for driving at night , especially in unfamiliar places. Please Green flag please pursue this matter.

  33. George Bennett February 12, 2018 7:56 pm

    When I lived in France in the early 60s the French had yellow head lights which reduced glare dramatically, why don’t we go back to this system as it did not seem to reduce the lights ability to allow us to observe the road ahead.

    • trevorjmallett February 19, 2018 3:12 pm

      The yellow lights were introduced during the Second World War to distinguish French vehicles from German ones.

  34. John Ketsi February 13, 2018 10:08 am

    Very good article on light dazzle but equally annoying is the lack of handbrake use at traffic lights etc., The high level stop lights are a great contribution to road safety whilst on the move but are extremely uncomfortable to sit behind particularly on a wet night ! . Perhaps the problem is predominantly caused by automatic vehicles ? . It would be nice if people resumed the use of the handbrake again when stopped at , say , traffic delays ?.

  35. bobbiewalkingtonBobbie Walkington February 13, 2018 1:02 pm

    Has the motor industry stopped fitting mud flaps? In wet weather or if there is standing water on the road driving becomes hazardous when following large vehicles that throw up clouds of spray which can then be exacerbated by oncoming traffic with the over bright lighting. Why oh why are motor manufacturers not making safety for road users their priority rather than adding ever more gadgetry to their vehicles. They should be held responsible.

    • J. Alexander February 14, 2018 5:39 pm

      Amen to everything you have said Bobbie. Comes to something when you feel you need to wear sunglasses to drive at night! I also think it is time to force manufacturers to THINK before they add more unnecessary lighting to cars.

  36. Tony Wicks February 14, 2018 10:14 am

    So many valid comments!!.– The greatest is for the driver to remember he is in control and responsible. To lift a finger to use the Direction Indicator seems beyond effort or worth to so many these days.

  37. Bernard J Harris February 14, 2018 1:37 pm

    Lots of excellent points made in these comments … I totally agree that the 55W law needs to be amended to restrict brightness. But no-one has yet mentioned the fact that headlight beams can these days be adjusted by the driver – and I suspect that many drivers have their lights on “maximum height” to make the beams show more of the road ahead. I thought there was a law about this – it seems to be ineffective!

  38. Michael Jones February 14, 2018 2:47 pm

    I agree with all these comments and am suprised that led headlamps were allowed in the fiest place as they have exceeded the lighting regulations. Bicycle led light are very dazzling and there should be legislation regarding the fitting and aiming of them.

  39. Gordon Lockwood February 15, 2018 7:54 am

    The law was I believe that it was main headlights 55/65 Watts with incandescent bulbs with a color temperature of 3000K, light is measured in lumens and modern HID and LED run at about 6500 K effectively twice the colour and much brighter in lumen power for less wattage so effectively the law as was has been bypassed,I wrote to MOT and they are doing a review this year but don’t hold your hopes up.Years ago in FOG you switched OFF your headlamps and ON the fog lamps ,no back glare as you we’re looking on top of the light beam,now we get the cars with DRIVING lights so they have 4 lights on the front increasing light pollution.need I say more,yes drive a bit slower in the dark and keep to existing lamps or alter the colour temperature of the led’s, it can be done. More eurotrash!

  40. Peter Edwards February 15, 2018 11:21 am

    The comments about handbrake are very valid but it is the modern trend for them not to be fitted on new models and have ‘automatic’ ones instead.

  41. Geoff Page February 15, 2018 4:40 pm

    Thanks for information & advice regarding very bright head lights p

  42. Richard Scott February 16, 2018 10:35 am

    Having sufered from being dazzled by oncoming headlights for years, I asked my optician about coated lenses for night-driving glasses and was told that they couldn’t prescribe them because they are illegal in the UK? Is this not the case then?

  43. Barbara Cooney February 16, 2018 4:10 pm

    An added problem for those of us who suffer from migraines is that very bright headlights (especially the horrible very blue/white lights) are known to trigger migraines in some people. The Migraine Association has been trying for years to get someone to address this issue.

    • Eric Hayman, February 17, 2018 7:56 pm

      When I was a child, of around 9 or 10 years old, I was a weekly boarder at a boarding school some 15 miles from my home. My parents would come in the car on a Friday evening and bring me home for the weekend, taking me back to school on the Sunday evening. The first stretch of road from the school had the 1950s yellow sodium street lights, while the second had bluish-white lights. The yellow lights gave me a bad headache, to the extent that I sat in the back of the car, shut my eyes and hid from them. Once we were in the bluish-white light area, I would emerge and enjoy their effect on my brain. Having been involved in photography for most of my life, I have become aware of “warm” and “cool” colours. The yellow lights would have been warm, and the bluish-white ones cool. As I became a teenager, the bad effect of yellow street lights faded. My maternal grandfather would take to his bed with migraines.

  44. Dave Davies February 16, 2018 5:37 pm

    As well as the bright light problem some people seem to try and counteract it by driving around with their headlights on full beam, even in built up areas near me. A quick flash of my lights seems to get a responding dip of the oncoming vehicles lights. If these people cant see to drive in the dark they should not be on the road, otherwise have some good old fashioned common road courtesy, before they cause an accident.

  45. Eric Hayman February 17, 2018 9:12 am

    I recently passed a cyclist with a bright flashing rear light – no problem there: it immediately identified him as a pedal cyclist. But when I stopped for red traffic lights, as he caught up the beam of his equally bright white headlight hit my right door (NOT wing mirror) and blinded me. I had to shut my eyes and wait until the effect of the glare had subsided before driving on. In doubt if the cyclist was aware of this dangerous effect of his front light. I have not seen so many responses to a Green Flag topic before. So these light problems must be very common.

    A friend has a new BMW that sets the angle of the light beams as soon as he starts the car, assuming that the car is on a level stretch of road or driveway. Another bit of dangerous modern gadgetry .

    • Bee February 17, 2018 9:19 am

      I have two cars. One is a 26 year old Land Rover Defender with very weak headlamps which won’t dazzle anyone ever. Downside is that on the country roads in the area where I live I can’t see much at night. The car has just passed its MOT without any advisories, so they must be legal. My second car is a new large BMW which has very bright adaptive lights. It also has an auto dim switch so I have never been flashed. It dips one or both lights depending what is in front, how well the street is lit – if at all.

    • David Field February 17, 2018 9:36 am

      I was being followed by a London bus, the lights of the bus were level with my rear and side mirrors. I could not look in my mirrors because I was being blinded by the intensity of the lights, I had to fold my wing mirror in until the bus was no longer in my view, In my opinion, this is a very bad and dangerous design fault, which London Transport should be made aware of.

  46. Alan H February 17, 2018 11:15 am

    this is a big problem i find not looking directly into a dazzling beam helps concerntrate your look to the road in front of you slightly to the nearside

  47. Colin February 17, 2018 11:22 am

    Isn’t there independent safety testing of all these problems caused by the latest lightning technology? And the manufacturer’s brought to book. Perhaps a campaign by independent motoring organizations and a online petition is in order, looking at the number of responses on this issue I think there would be plenty of signatures.

  48. g February 20, 2018 10:43 am

    I really don’t get the need for brighter and brighter headlamps – all it suggests to me is the need / want to drive faster in conditions unfit for that want / need by those who use them. That selfish need is put before the use of the roads by others more vunerable using the roads who become even more vunerable because of the use of these bright headlamps.

  49. peter chatfield February 20, 2018 5:50 pm

    All the valid comments lead one to the conclusion that a review of vehicle /cycle lighting regulations is long overdue.The safety of one road user should not compromise the safety of many others

  50. George Moorfield February 20, 2018 10:34 pm

    Headlamp alignment is part of the MOT test to ensure oncoming vehicles are not dazzled or blinded by your dipped beam. Cannot the same test be done to new cars before they are sold?

    • Eric Hayman February 21, 2018 8:27 pm

      As I have said, my neighbour friend with a 67 plate BMW tells me that after leaving his sloping driveway he has to stop on a level stretch of road, turn the ignition off and then on again for the headlights to set themselves at the correct level. Otherwise they are set far too high because his driveway slopes down towards the road and he – rightly – always reverses into the driveway. Were he to drive forwards into the driveway then reverse out onto the road, then the headlights would be set too low! He can’t win.

Leave a Reply