Why Are Modern Car Headlights So Blindingly Bright?

Intensely bright, blue-tinted headlights flooded my hatchback when I was cruising at 80 mph on the highway connecting San Antonio and Austin. These lights were so dazzling that they created such a strong reflection in my rearview mirror that it seared my eyes, forcing me to glance away from the road and abruptly reduce speed. A massive luxury SUV started following closely behind me—amplifying the blinding effect—and then swiftly sped past after making a forceful lane change.

For a brief instant, everything seemed normal. My vision adapted, and I started accelerating once more—only to be blinded by a raised pickup truck equipped with even more intense headlamps and additional spotlights mounted on its roof. Following this, another vehicle caught my eye: an electric one adorned with the brightest lights I had ever encountered, followed by numerous others. Dreading the possibility of getting hit from behind each time I needed to reduce speed and divert my gaze from the road, I exited the freeway and opted for an alternate path instead.

Recently, the headlights seemed particularly harsh on my eyes. Perhaps I was simply aging, or maybe my vision had deteriorated from spending so much time in front of a computer screen.

Next, a follower of Vox’s Explain It to Me Podcast host Reed reached out and queried, "Is it just me losing my mind, or do all the latest cars on the street seem to be equipped with exceptionally intense headlamps? I'm curious about what might be causing this recent trend. Also, are there regulations governing these lights? Can individuals freely install anything they choose at the front of their vehicles without potentially blinding others?"

He wasn't alone. Our program has gotten numerous emails containing comparable queries from both listeners and readers of Vox. Additionally, there’s even a subreddit devoted to discussing issues where individuals voice complaints, share humor, and collaborate to find resolutions. Thus, with the aim of assisting Reed, me, and numerous other disgruntled drivers, Explain It to Me took on Reed’s question.

Is the brightness of car headlights increasing?

John Bullough, who heads the Light and Health Research Center at the Icahn School of Medicine at Mount Sinai, explained to Vox that there are two approaches to addressing this query.

The initial issue pertains to the hue of LED lights, which have become predominant in automobile headlamps. "It’s likely you've observed that many of these appear much closer to a bluish-white shade as opposed to the yellowish-white glow emitted by older halogen headlight bulbs," explained Bullough. Halogens were previously more prevalent for this application.

The units used to gauge light intensity—lumens and candelas—were established by scientists in the past and do not completely account for varying visual sensitivities across different colors of light, according to Bullough. This implies that although a light meter may indicate equal light intensity from both halogen and LED headlight pairs, human eyes perceive the blue-tinged LEDs as brighter due to their higher likelihood of being detected peripherally, causing our brain to consider them more significant or urgent.

Bullough mentioned that the second aspect is the heightened intensity of headlights, which has significantly risen during the past 10 to 20 years.

"If we consider why vehicles have headlights, they aren’t meant to cause glare; rather, they're designed to assist drivers in seeing objects on the roadway to prevent accidents," he explained. However, this has led to efforts aimed at making cars safer for passengers, such as the continually growing dimensions of U.S. automobiles Moreover, the escalating brightness of headlights has led to a fresh array of safety concerns for pedestrians and cyclists.

Who is accountable for the increased lighting?

Headlight brightness levels have risen partly due to factors such as the Highway Loss Data Institute “safety scores,” which the insurer-funded non-profit organization provides to assist consumers in selecting their next vehicle, according to Bullough. Automakers also leverage these scores as a marketing tool.

When IIHS first started evaluating headlights nearly a decade ago ," they weren't rating headlamps highly when it came to helping us visibility during nighttime." Out of the 95 car models evaluated by the IIHS in 2016, only two received a top score. .

The urge to enhance safety scores, along with the increasing prevalence of LED technology in the overall lighting industry, has compelled automotive manufacturers to significantly increase the brightness of their headlights.

"LEDs represent a cutting-edge technology that has revolutionized nearly every aspect of the lighting industry over the past fifteen years," noted Nate Rogers, a freelance author who penned an exhaustive study. In 2024, discussions around headlight intensity became prominent as new regulations aimed at enhancing nighttime driving safety were proposed. These changes focused on ensuring headlights emitted sufficient luminosity to improve visibility for drivers without causing glare issues for those approaching from the opposite direction. The advancements in LED technology played a key role in achieving this balance between illumination and driver comfort. LEDs consume less energy and have a longer lifespan. Their introduction marked a significant transformation in the lighting industry, gradually replacing almost all types of illumination, including those used for vehicle headlamps.

But Rogers also believes the federal highway safety czars, the National Highway Traffic Safety Administration (NHTSA), share some of the responsibility for why bright LED lights have become the norm on roads. “They are the ultimate authority,” he said. “Any car that is driving on the road has to meet NHTSA standards.”

Multiple individuals I talked with at NHTSA mentioned that they receive the highest number of driver complaints regarding car headlights and their brightness," Rogers stated. However, NHTSA hasn't established regulations to control the strength of these intense lights. Neither do federal safety ratings For car models, consider the safety of all occupants. outside The vehicle, as David Zipper from Vox clarified earlier this year — solely the occupant safety of the particular car is taken into account.

Can brighter lights really be hazardous?

During his reporting, Rogers said, he never really found anyone disputing safety concerns tied to headlight glare. While he was often pointed to an IIHS study Finding a 19 percent decrease in accidents among vehicles with high-rated headlights for safety, he noted, it’s extremely challenging to monitor whether an individual was involved in a collision due to being blinded by another vehicle's lights. "Lacking precise data on the danger posed by the intensity of car headlights," he explained, "it appears that NHTSA is somewhat stalled and uncertain about addressing this issue."

Driver safety constitutes only one facet of the issue. Another critical concern involves individuals who share the roadways—pedestrians and cyclists alike. Over the past ten years in the U.S., the fatalities among those walking due to car accidents have surged dramatically; statistics reveal this concerning trend according to data from various sources. new report from the The Governors Highway Safety Association (GHSA) Pedestrian fatalities have increased by 48 percent since 2014. Additionally, GHSA report found that in 2022, “approximately three-quarters (77%) of pedestrians killed in fatal crashes were struck at night.”

Mark Baker, founder and president of the advocacy group the Soft Lights Foundation , which seeks to safeguard individuals from the adverse impacts of LED lighting, suggests that high-intensity headlights, coupled with the growing number of larger vehicles on U.S. roadways, could be contributing factors to the rise in nighttime pedestrian fatalities. He hypothesizes that drivers dazzled by intense lights at night find it difficult to spot pedestrians, and vice versa. "The amount of illumination has become excessive," he remarked. "It leaves everyone practically invisible."

Baker has campaigned for Congress to secure a hearing regarding the negative effects of LED headlights, and he has attempted to collaborate with various states to enact legislation regulating headlight brightness. Although he hasn’t achieved success yet, over 70,000 individuals have signed his petition titled " Prohibit Glare-Inducing Headlights and Prevent Fatalities! ”

I've submitted two petitions to the federal government," Baker explained. "The first petition aims to establish an upper threshold for maximum intensity levels." Currently, there are no regulations setting such limits. Additionally, my second petition addresses the absence of restrictions on blue-wavelength light, which is particularly harmful as it leads to significant eye strain and reduces visibility, posing serious risks to our vision health.

The conflict is deeply personal for Baker. "They took me out of teaching," he stated. The sight of LED headlights both on the roads and in his classroom caused significant distress—this ordeal ultimately resulted in a diagnosis of mild autism. He explained, "I was unable to go to work." Consequently, he dedicated himself to understanding why these LEDs were causing such issues. Since then, he has encountered others who experienced equally intense reactions, leading some to contemplate suicidal thoughts due to how tormenting this condition can be for individuals with autism.

Will we ever stop headlight glare?

If safety ratings motivate automakers to install bright LED headlights in new vehicles, then what should be our next step?

Several approaches might shield drivers from glare, according to Bullington. One involves adjusting headlight aim; specifically, lower beams—which are commonly used—should direct their illumination downward onto the roadway rather than reflecting off the back windows of vehicles ahead. However, these headlights may lose proper alignment following replacements or collisions.

Adjusting the alignment of headlights is a requirement for safety inspections in some states, though not all," explained Bullard. "Therefore, motorists can request their mechanics to check and correct the headlight aim during their annual inspection.

According to automotive and technology journalist Tim Stevens, the alignment of headlamps tends to be particularly inadequate in older vehicles equipped with after-market LED lights. Stevens believes that stricter implementation of traffic safety regulations might address this issue.

“Many states such as Michigan do not conduct any type of annual inspections,” he explained. “Therefore, it becomes a matter for the police to stop someone if they believe the person's headlights are excessively bright.”

The NHTSA might establish headlamp luminosity caps, serving as a foundation for regulatory oversight by state and municipal agencies, according to Bullough and Baker. "Definitely, one could impose certain maximum levels of brightness from low-beam light fixtures," noted Bullough.

Stevens mentioned that automakers are implementing advanced technologies aimed at mitigating this issue, such as high beam assist or adaptive beam technology. These features are designed to automatically lower the headlight intensity when approaching vehicles, pedestrians, or poorly lit areas.

It has been accessible in Europe and globally for several years," Steven explained. "Since 2022, it became legalized in the U.S., yet due to the lengthy process car makers require to introduce new technologies, it will take additional time for these innovative headlamps to reach the American market." He further noted that currently, "this technology will solely appear on the latest and most premium models. Therefore, it could be quite a while until we observe these headlight systems becoming common across the broader spectrum of vehicles on our roads.

Various methods are available for individuals to manage headlight glare, such as glancing downward and toward the right side when encountering bright lights from oncoming vehicles, or investing in a pair of blue-light blocking spectacles. However, Baker feels that substantial improvement will be achieved solely via active community involvement.

The strength lies in listeners reaching out to the government, connecting with me, teaming up with the Soft Lights Foundation, and taking part," he stated. "Let’s address this systemic issue.