Are headlights too bright? Everything you need to know about headlight glare

Headlight glare (or headlight dazzle) describes when the main lights fitted to a vehicle dazzle other road users, a phenomenon that is most likely to be experienced at night. 

RAC research suggests some headlights do cause glare. In the most recent research released in February 2025, almost all drivers surveyed said they find at least some car headlights too bright. This may be from dipped headlights, and/or headlights that are on full/main beam.

Yes, figures from the RAC suggest the problem of dazzling headlights is getting worse. As many as six-in-10 drivers (61%) surveyed in December 2024 who say they are affected by headlight glare believe the problem has got worse in just 12 months.

At best, headlight glare can make driving uncomfortable and more difficult - this is referred to as 'discomfort glare'. But the consequences can be more severe. Half of drivers affected by glare who were surveyed by the RAC said they are temporarily blinded, while four-in-10 say they feel less safe driving as a result of bright headlights on other vehicles. Others report tiredness, headaches and even migraines:  

But as alarming is the proportion of drivers affected by glare who say they have either reduced the amount they drive at night, or even stopped completely:

The RAC understands there may be a number of reasons why drivers suffer from headlight glare. It’s also likely to be the case that different people perceive and react to dazzle to different extents.

Firstly, it may be down to the alignment of the headlight. If it is angled incorrectly, it is more likely to dazzle other people. If in any doubt, get your vehicle checked by a good quality garage. Data shows that of the 32.4m MOT tests carried out in 2022 on Class 4 vehicles in the UK – which includes cars – as many as 1.6m failed due to misaligned headlights.

Newer lighting technologies, with the increase in vehicles fitted with full LED headlight systems, may also help explain the increase. This is because the human eye reacts to LED lights in a different way to more ‘yellower’ halogen beams that can cast a more diffuse light. What’s more, cheap aftermarket LED bulbs – which are not road legal in the UK – may also be being increasingly fitted by drivers replacing their car headlight bulbs, and contributing to the problem.

The increasing prevalence of vehicles that sit higher on the roads – typically SUVs (Sports Utility Vehicles) may also be a factor, with drivers who are in cars that sit lower on the road more likely to be adversely affected. RAC research released in February 2025 shows that more than half of dazzled drivers (56%) of conventional cars like hatchbacks blame higher vehicles, whereas only 28% of those in higher vehicles point the finger at similarly sized vehicles. See the chart below.

RAC research shows drivers are split on the causes of glare. Given the complexity of the topic, the RAC called on the Government to commission independent research to understand the true reasons for headlight glare, and to work out what can be done. In positive news for drivers, this call was heeded in 2024.

Highway Code Rule 114 states drivers MUST NOT:

• use any lights in a way which would dazzle or cause discomfort to other road users, including pedestrians, cyclists and horse riders
• use front or rear fog lights unless visibility is seriously reduced. You MUST switch them off when visibility improves to avoid dazzling other road users (see Rule 226).

It also states that in stationary queues of traffic, drivers should apply the parking brake and, once the following traffic has stopped, take their foot off the footbrake to deactivate the vehicle brake lights. This will minimise glare to road users behind until the traffic moves again.

The ‘must not’ line in the Highway Code indicates it is backed up by law, in this case the Road Vehicles Lighting Regulations 1989.

Headlights on all new vehicles sold in the UK have to pass a rigorous ‘type approval’ process before they are permitted for use.

Yes, the alignment of headlights is checked at the MOT. However, the RAC is aware that alignment is a part of the test that some garages find more difficult to perform. In 2016, the Driver and Vehicle Standards Agency (DVSA) said that ‘headlamp aim consistently tops the MOT compliance survey as one of the most likely items to be assessed incorrectly by testers’.

Since 2013, there has been an average of 280 collisions a year where dazzling headlights were a contributory factor. However, it’s worth noting that these collisions are only those where a police officer attending the scene can be sure that headlight dazzle was a factor.

What’s more, just because there aren’t collisions caused by dazzling lights doesn’t mean there isn’t a problem. If drivers are feeling less safe and less confident as a result of them, or if they’ve reduced the amount they drive (or even stopped driving) as a result of glare, this suggests there is an issue.

No, it’s not. Additional research from other motoring organisations elsewhere in Europe, including the FIA, ADAC in Germany and ANWB in the Netherlands, backs up the RAC’s figures that highlight the concern a lot of drivers have.

The RAC first raised the issue of headlight glare with the UK Government in 2018. Since then, it has commissioned a series of pieces of research to highlight the extent of the problem, and the impact it is having on drivers - most recently in February 2025. It works closely with other organisations that have an interest in the issue, including the College of Optometrists and IAM RoadSmart. The RAC also contributes its findings to European and international groups that are examining the topic.

Yes. In 2024, the work of the RAC and its partners on this campaign were successful in getting the Government to commission its own independent research into headlight glare. The Department for Transport appointed TRL, a Berkshire-based company, to run the project. As part of this, it is completing on-road testing as well as a scientific review, during the winter of 2024-25. The UK Government will then consider its recommendations, likely summer 2025.

RAC senior policy officer Rod Dennis said: “With the exception of potholes, few motoring topics seem to rouse as much interest among the nation’s drivers right now as bright headlights. It’s undisputable that public concern is increasing, but the reasons for glare and what can be done to reduce it aren’t nearly as clear. That’s why we’re pleased the Government heeded the calls of the RAC and our partner organisations on this issue and commissioned an independent project to look into it. We’re aware other European countries are now taking the matter seriously, too.

“What has gone from a mere frustration is now having a profound impact on people – whether that’s momentarily being blinded while driving or struggling to judge the speed or position of a vehicle ahead. The fact such a high proportion of people are also driving less at night – or wish they could – is remarkable and demonstrates the need for glare to be tackled. This does, however, need to be balanced with the potential road safety benefits afforded to people driving vehicles with brighter headlights.

“Our research does suggest that the difference in height of vehicles affects how drivers perceive glare, as does the colour of headlights on oncoming traffic. It also appears to be more of a problem on unlit roads, where drivers’ vision is subjected to greater levels of contrast.

“We hope our findings prove to be valuable to both industry and government in understanding the effects dazzling headlights are having on drivers. At the same time, we’re pleased to be able to dispel some myths around the topic, such as the one that headlight glare is something that affects only older drivers. Interestingly, drivers under the age of 35 are more likely to say most vehicle headlights are too bright.”

Baroness Dianne Hayter, who has worked with the RAC to campaign on this issue, said: “As the RAC's latest detailed study shows, virtually every driver experiences the problem of over-bright headlights, and many find the dazzle sufficiently problematic to stop or reduce their driving at night, with real social and other costs. The RAC has produced the evidence, now the Government needs to take action – whether on the colour, intensity or angle of these glaring lights.”

Denise Voon, clinical adviser at The College of Optometrists, said: “Optometrists are hearing from our patients more and more frequently that they’re having issues with night driving because of headlight glare from oncoming vehicles. Motorists must always wear their prescribed glasses or contact lens for driving, including at night, and we urge anyone experiencing issues with their vision while driving to contact their local optometrist for advice. 

“However, more motorists are experiencing issues with their vision while driving at night earlier than we’d expect them to be impacted by age-related eye conditions, such as cataracts. We look forward to the findings from the government’s headlight glare research project and hope this evidence enables the industry to find a solution that will reduce headlight glare and make driving at night safer for everyone.”

The College of Optometrists, which the RAC works closely with on this topic, recommends the following top five tips to help make it easier when driving at night:

• Keep your windscreen clean and smudge-free to reduce the impact of glare
• If you wear glasses, ensure they’re clean and smudge-free too
• Stay up to date with sight tests with your local optometrist to ensure your glasses help you see as well as possible when driving and your eyes are healthy.
• When presented with bright oncoming headlights, keep your eyes open and cast your eyes to look at the curb or side of the road. This will keep you safe and help minimise the effect of adaptive and discomfort glare.
• Finally, be considerate when driving and dip your headlights when required. If you have automatically dimming headlamps, remember they don’t always pick up oncoming cars, cyclists and pedestrians, so know how to dip them manually.

In addition, adjust your rear view mirror at night to reduce the effect of bright headlights behind you. Newer cars have self-dimming mirrors that can also help, although you may notice you still experience unavoidable glare through your wing mirrors.

If you are dazzled while driving it’s important to safely slow down, or even stop your vehicle until your vision improves. 

The irony of dazzling headlights is that in many cases drivers won’t be aware of how they themselves may be partly the cause of the problem.

It’s important to ensure your headlights are angled correctly, according to the load you are carrying. That’s because a car with rear passengers and a fully loaded boot will naturally cause the front of the car to be positioned slightly higher on the road, compared to a car that just has the driver in it. Check your car handbook for how to align the lights, and adjust accordingly. Some newer cars adjust headlights automatically based on the load carried.

If you regularly get flashed by other drivers at night, it may be because they think your headlights to be too bright. This could be something you talk to a good quality garage about, either as part of the MOT or at another time.

Are you affected by headlight glare? If you have a story to tell, please share it in the comments below.