Many drivers are unaware of an essential function of the rearview mirror, which helps prevent glare while driving at night.

Driving after dark poses different challenges than during the day.

While traffic tends to flow more freely, visibility decreases considerably, and consequently, risks increase.

One of the most common problems is glare from other cars’ headlights, which can be dangerous for drivers.

How the Car’s Secret Button Works

To counteract this problem, most vehicles have a secret button on the rearview mirror.

This feature, which has been around for decades, reduces the glare from lights coming from behind, making nighttime driving safer.

Simply pressing a tab or lever causes the mirror to dim the incoming light.

In newer models, this system has become automatic thanks to electrochromic rearview mirrors.

These mirrors detect light intensity and, using sensors and a special coating, darken their surface to prevent glare.

When the distracting light disappears, the mirror automatically returns to its original state.

Impact on nighttime driving
According to the Directorate General of Traffic, while most accidents occur during the day, nighttime accidents tend to be more serious.

Specialists warn that drivers’ vision is reduced by up to 20% at night, making it difficult to perceive distances and obstacles.

Therefore, activating the car’s secret button is a fundamental measure to protect against glare and reduce eye fatigue.

Some high-end vehicles even extend this technology to exterior rearview mirrors, and the latest trends point to digital rearview mirrors with cameras and screens that automatically adapt to lighting conditions.

Being aware of this feature can make all the difference when it comes to driving safely in the dark.