Almost Nobody Uses This Button on the Rearview Mirror… But Everyone Should Know About It
Most drivers use their rearview mirror every time they get behind the wheel. They adjust it, glance at it, and rely on it constantly. Yet many people never notice that some rearview mirrors have a small lever or switch underneath—and even fewer know what it does.
It may not look like much, but this simple feature can make night driving significantly more comfortable.
The hidden purpose of the rearview mirror switch
If your vehicle has a manual rearview mirror, you may find a small tab or lever at the bottom.
Its purpose is to activate the mirror’s night mode, sometimes called the anti-glare setting.
When bright headlights from vehicles behind you are reflected directly into your eyes, the glare can be distracting and reduce visibility. Flipping the lever changes the angle of the mirror’s reflective surfaces, reducing the intensity of those lights while still allowing you to see traffic behind you.
How it works
Traditional rearview mirrors are designed with two reflective surfaces.
In normal daytime mode:
- You get a bright, clear reflection.
- Visibility is optimized for daylight conditions.
In night mode:
- The mirror redirects the brighter reflection.
- Headlight glare is reduced.
- The image appears dimmer but remains usable.
The result is less eye strain during nighttime driving.
What about modern cars?
Many newer vehicles use auto-dimming rearview mirrors instead of a manual lever.
These mirrors contain sensors that detect bright light from behind and automatically darken the mirror surface when necessary.
Drivers often don’t notice the feature because it works without any input.
When should you use it?
The manual night setting is most useful when:
- Driving after dark
- Following busy highways with heavy traffic
- Experiencing discomfort from bright headlights
- Driving in rainy conditions when glare is amplified
Switching between modes takes only a second but can make long nighttime journeys more comfortable.
A small feature with a big benefit
Cars are full of features that owners never fully explore. The rearview mirror’s anti-glare setting is one of the simplest examples—a small lever that many drivers overlook for years.
While it won’t transform your driving experience overnight, it can reduce eye fatigue, improve comfort, and make nighttime driving safer.
The bottom line
That little switch beneath your rearview mirror isn’t a mystery button—it’s an anti-glare feature designed to help you see more comfortably at night. If your vehicle has one, it’s worth knowing how it works.
Sometimes the most useful features in a car are the ones hiding in plain sight.