While we've all probably noticed the little tab under our car's rear view mirror, most of us will wrongly assume it's to lock the viewing device in place to stop it moving about. However, it has a much more important function that not many know about.
Many drivers hate driving on a night time, with the low visibility through darkness reduced further by gleaming and glaring headlights on the roads. And to make things worse, you'll sometimes get people driving about with their blinding full beams on - especially on country roads where there are no streetlights.
But these pose a problem to other motorists, who could find themselves in an accident after being shined out by the powerful rays. A report conducted by the National Highway Traffic Safety Administration (NHTSA) in fact shows that many drivers complain of headlight glare and reduced visibility - the latter being directly linked to an increased risk of crashing.
Read more: Drivers stunned after discovering 'secret' compartment hidden in car they never knew about
The Mirror reports that manufacturers seem to have been thinking one step ahead, however — many cars contain a secret button that can take a bit of the edge off the glare. One TikTok user, @everythingbrooklyn, demonstrated the button in a video that has garnered over two million views and over 96,000 likes.
"Me flipping the rear view mirror tab so the headlights don't blind me," she captioned it. Underneath the rear view mirrors of many cars is a small tab that, when flipped, angles the mirror in a different direction so that the beams of light don't hit it the same way.
That essentially reduces the glare, since the light is directed down past the eye instead of into it, but just because the glare is reduced from ordinary headlights doesn't mean it's reduced from the sun or from full-on bright beams. The button is designed for specific use only - but when it's used, it works.
Many TikTok users flocked to the comments section of @everythingbrooklyn's post to express their shock at discovering the feature existed. @natbr24 wrote: "I didn’t know about this either until a few weeks ago and my life has been changed ever since," while @regan.piercee added: "Never knew that’s what that little tab thing is for."
Others, however, were quick to tease the people who didn't already know about it.
"How did none of you know this," wrote @gr3y5999, while @oliviaaa.615 said she thought everyone knew about the feature. Regardless of whether or not individuals knew about the feature, it exists, and it's designed to help drivers traversing the roads at night, but will it prevent accidents?
That's unclear, according to the NHTSA survey. A direct correlation between headlight glare and accidents has not been made, though the report does state that reduced visibility can lead to crashes.
Studies are still being conducted on headlight glare and its effects, and results are still trickling in.
Many law firms have tried to argue that the phenomenon led to crashes. Some, like Wagner & Wagner, an injury law firm, argue that the bright lights make it impossible to see moving objects, leading to crashes. That would therefore make those with bright headlights liable in accidents.