Skip the auto shop - Our mechanics make house calls
  1. Home
  2. Articles
  3. What Does the Switch on the Bottom of the Rearview Mirror Do?

What Does the Switch on the Bottom of the Rearview Mirror Do?

rearview mirror switch

Auto mirrors provide essential visibility to the rear and sides of a vehicle. However, they can also be sources of discomfort – being blinded by the glare of headlights behind you through your rearview mirror is no fun, and reduces your safety on the road. Thankfully, it’s simple to adjust the mirror by using the switch at the bottom of the rearview mirror.

What does the switch do?

If you have a manual rearview mirror, there’s a switch or tab at the bottom. It should move up and down. Changing the switch’s position changes the way the mirror works. Flip it one way and you’re in daytime driving mode, with everything crisp and clear. Flip it the other way, and it changes to nighttime driving mode. The reflection is dimmer (and harder to see when it’s light outside), but it is meant for nighttime driving and dims the glare from headlights behind you.

How the switches work

So, how does the mirror switch actually work? It’s pretty simple, really. Your rear view mirror glass isn’t actually flat – it’s a wedge of glass that’s thicker on one end than the other. When you flip the switch at the bottom of the rearview mirror, the wedge moves. What this does is change the way light passes through it and how it’s reflected back.

In daytime driving mode, the back surface of the mirror is what reflects light and images. When you flip the switch and change the orientation of the mirror glass, the front section is responsible for what you see. Because the light and images must first travel through the back side of the glass before hitting the front and bouncing back to you, the image is dimmer and the glare of headlights behind you is greatly reduced.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

How to Buy Fuel Treatments
Adding a fuel additive to your gas tank when you fill up is one way to clean vital engine parts of deposits, improve the performance of your engine,...
The Traveler’s Guide to Driving in Malaysia
CraigBurrows / Shutterstock.com Malaysia is a popular destination for many tourists today. The country has amazing sights and attractions that you will want to explore....
Veteran and Military Driver Laws and Benefits in Idaho
The state of Idaho offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch in the...

Related questions

Q: Q: How do I adjust the rearview mirror?

Having a clear, unobstructed view out the back window of your car is vital. You need to see behind you while you’re on the road, when you’re backing out of a parking space and more. Whether you have a manual...

Q: Dome lights and courtesy lights in back seat will not turn on.

Hi there. When multiple objects in a car will not work that are electrical, then there is a loose or broken ground wire to the circuits. Check all of the wiring in the cab to see what could be loose...

Q: Q: How do I adjust the rearview mirror?

The rearview mirror is an extremely important safety feature that provides you with visibility through your rear window. Before driving, you should always adjust your rearview mirror so that you have maximum visibility. You can adjust the mirror manually, by...