Modern LED headlights, intensified by their widespread use in sport utility vehicles (SUVs), are increasingly blinding drivers globally, creating a significant road safety concern that current regulations fail to adequately address.
Studies show an overwhelming majority of motorists are regularly distracted by the glare from oncoming vehicles. Research from British consultancy TRL indicates 97% of drivers report being distracted either regularly or occasionally by intense headlights.
The problem stems from the significantly increased luminosity of modern lighting technology. Over a decade ago, halogen lamps rarely surpassed 1,300 lumens, but today’s LED lamps can emit over 4,000 lumens, producing a much brighter, whiter light.
Peak luminosity measurements reached 63,566 candela per square meter (cd/m²), far exceeding the widely accepted safe limit of 40,000 cd/m².
British Member of Parliament Martin Wrigley, cited by Le Figaro, stated that LED headlights can be up to 10 times brighter. He added that the intense glare can cause stress, requiring 30 to 60 seconds for drivers to recover their vision.
While vehicle headlight power is regulated by international standards such as ECE R149, these rules do not account for “luminance.” This term refers to the perceived brightness of light as it is received by the human eye.
Luminance is measured in candela per square meter (cd/m²), also known as nits.
TRL’s analysis found an average maximum headlight intensity of 15,860 cd/m², but with peaks that frequently surpassed the 40,000 cd/m² acceptable limit. Researchers observed these limits are “frequently exceeded, especially in certain road configurations: uphill, curves, SUV crossings, [and] wet conditions,” according to French publication Auto Plus.
High headlight intensity accounts for 23% of the glare problem. Vehicle type contributes another 20%. Nine of the ten vehicles most frequently associated with LED headlight glare are SUVs, and eight out of ten of these are equipped with LED lighting.
To prevent dazzling others, drivers should ensure their headlights are properly aimed. A simple check involves parking five meters from a wall, marking eye height, and verifying that the low beam line sits slightly below the mark. Adjustments can also be made using an in-car height correction button, particularly when the vehicle is heavily loaded, which can raise the front end and alter beam direction.
Maintaining the vehicle’s optical assemblies is also crucial. Older polycarbonate lenses can become opaque, diffusing light irregularly and projecting beams too high. These can be restored by polishing or replacement.
To minimize being dazzled by other vehicles, experts recommend keeping windshields meticulously clean, as dirt can exacerbate the effect of intense headlights. Drivers can also slightly avert their gaze to the right when faced with oncoming lights.
Specific night driving glasses, used under medical guidance, may offer some relief. Additionally, applying an anti-reflective film to the internal rearview mirror or slightly adjusting external mirrors downwards can help mitigate glare.