The secret car button that almost no one knows about and is key to driving at night

Many drivers don’t realize their rearview mirror has a built-in feature designed to improve safety at night.

Driving after dark reduces visibility and increases accident risk, especially due to headlight glare from cars behind you.

To address this, most vehicles include a small tab or lever on the rearview mirror that changes its angle.

Flipping the tab dims reflected light, reducing glare and preventing eye strain during nighttime driving.

In newer cars, electrochromic mirrors perform this function automatically by detecting bright light and darkening the mirror.

Once the glare disappears, the mirror returns to normal without any action from the driver.

This feature plays a bigger role in road safety than many realize, as nighttime vision can drop by up to 20%.

Knowing and using this mirror function helps drivers stay focused, comfortable, and safer on the road after dark.