Having proper back and side view mirrors is crucial. However, they may also be causes of annoyance: it’s no fun to drive with your night vision impaired by the brightness of oncoming headlights in your rearview mirror. Using the switch at the mirror’s bottom makes adjusting the angle a breeze.
What exactly does the switch do?
A manual rearview mirror will have a tab or switch on the bottom. There need to be upward movement. The functionality of the mirror can be adjusted by moving the switch. To switch to daylight driving mode, simply flip the switch. To switch to nighttime driving mode, simply flip the switch. The reflection is less bright (and more difficult to perceive) because it was designed to reduce the glare of oncoming headlights during nighttime driving.
How the switches function?
The mirror switch: how does it function, exactly? It’s pretty easy, really. The glass in your rearview mirror is actually shaped like a wedge, with the thicker end towards the driver. The wedge can be adjusted by flipping the switch located below the mirror. It modifies the transmission and reflection of light.
When the sun is out, the mirror’s reverse side reflects what the driver sees. When you flip the switch and change the way the mirror glass is facing, what you see depends on the front part. Because light and images must first pass through the rear side of the glass before hitting the front and bouncing back to you, the image is darker and the glare from headlights behind you is substantially reduced.