Have you had your retinas melted by bright car headlights lately? Same here! The days of dim, warm-toned headlights are long gone, and in their place are bright headlights that appear to send the light of a thousand suns directly into our eyeballs. So why is this the case – and how have we now become the deer?

The short answer is: lighting technology has drastically improved

We’ve gone from acetylene or oil lamps in the very early days of vehicles; to the first high and low beam lights in the 1920s; to halogen and Xenon; to light-emitting diodes (LEDs) and laser lights today. Where the old halogen lights might have put out somewhere between 700 and 1,200 lumens of light, modern headlight tech is capable of putting out ten times that – though legal limits do apply in Australia.

LEDs, laser and high-intensity discharge (HID) headlights have made it possible to have very efficient, long-lasting and bright illumination when driving at night, so of course people prefer using them. Over time the older and dimmer headlights have aged out, and new cars now typically come with bright lights as standard.

Another factor: cars are getting bigger

Even as recently as 2012, the majority of cars purchased in Australia were low passenger cars that featured headlights at a lower height. Today, SUVs account for 55-60% of car sales in Australia. Taller cars naturally mean higher headlights. So if you happen to be driving a lower-set car like a hatchback or sedan, you’re probably more likely to encounter bright light from a 4WD.

Are strong headlights safer?

It makes sense that when you’re driving in a car, bright headlights would make your drive safer. And indeed in a 2021 study, nighttime crash rates were actually found to be around 19% percent lower for vehicles that had good-rated headlights.

But the question remains as to whether bright car headlights are safer for everyone. There are countless critics saying that for pedestrians and other drivers, bright headlight glare is distracting, unsafe and straight-up annoying. At one point, the National Highway Traffic Safety Administration in the US was receiving more consumer complaints about headlights than any other topic. There are also several advocacy groups calling for LED light bans!

How bright is too bright?

Back closer to home, we have an Australian Design Rule (ADR) as part of the Road Vehicle Standards Act 2018, which specifies “the photometric requirements for headlamps which will provide adequate illumination for the driver of the vehicle without producing undue glare for other road users.” In simple terms: the rules for headlights that don’t dazzle others. The ADR sets out aspects like intensity and position of headlights to avoid glare. Each of the states and territories has their own penalties for causing glare to others, as well as rules for aftermarket head lamps such as light bars.

Colour is a factor too

As well as becoming brighter, modern LED and HID lights tend to be higher in colour temperature. This is why you might have noticed more lights with a bluish-white tone. Those blue light emissions help to mimic daylight more closely and improve visibility. Unfortunately, blue light also has the highest energy of all visible light and can lead to more intense glare – as well as having not-so-great effects on some important things like circadian rhythms and melatonin production. In Australia, we actually have wavelength parameters to ensure headlights aren’t emitting anything other than white or selective yellow light.

Tips for more pleasant night driving

Part of the blinding-light problem is that night-time glare can be multifaceted. It could be due to headlight brightness, but it could also be due to smudged headlight covers, misaligned headlights, environmental conditions or even the eyesight of the person seeing the headlights. So here are some quick tips for the best night-driving experience:

• Clean your windscreens, inside and out.
• Dim your dashboard lights if possible to reduce overall glare.
• Redirect the air vents away from your face, as dry eyes can also hinder vision quality.
• Have your vision checked. Nope – we’re not trying to gaslight you, but half of all Aussies have a long-term eye condition, so this can help to rule out your own eyes from the equation!
• Look for LED headlights with a maximum of 2,500 and 3,000 lumens per bulb to avoid being that guy on the road.
• Adjust your own headlights according to your car’s weight, as many cars have adjustable headlight angle settings.

Is there hope on the horizon - or only more blinding lights?

Headlight and car manufacturers have long been adapting their designs to improve the driving experience, both for the driver and for other road users. There have been a raft of different designs and technologies over the years, but these have generally covered two categories:

• Headlights that lower intensity or create a dark spot when another object is detected, in order to reduce glare for that object.
• Headlights that adjust with the car’s steering as it navigates bends in the road.

The newest headlights, known as adaptive or smart headlights, tend to do both, providing great illumination for the driver as well as a better experience for everyone else. These technologies are becoming increasingly common in cars here in Australia including in certain Ford, Hyundai and BMW models, so you can already find these in various pre-owned cars and second-hand cars today.

So there you have it. You’re not going crazy when you have to squint at night, because headlights really have become brighter. Until smart headlight systems become the norm, though, we'll all just have to keep wondering if that approaching vehicle is a car or a small aircraft making an emergency landing.