A rear view mirror shows you what is behind your vehicle without turning your head
The rear view mirror is the mirror mounted on the inside of your windshield, usually near the top center of the car. It reflects what is behind you so you can see traffic, pedestrians, and obstacles without looking over your shoulder. Most rear view mirrors can be adjusted to point downward or to the side, and many modern ones have a button or lever to switch between normal and dimmed modes for nighttime driving.
The mirror serves one main purpose: to reduce blind spots and help you make safer decisions while driving. When you check it before changing lanes, braking, or reversing, you gather information about what is happening behind you. This is different from your side mirrors, which show what is beside you, and your direct view, which shows what is in front.
Key Takeaways
- The rear view mirror reflects traffic and objects behind your vehicle so you can see them without turning your head.
- You should check your rear view mirror every 5 to 10 seconds while driving, and always before slowing down, changing lanes, or reversing.
- Most rear view mirrors have a dimmer switch or lever to reduce glare from headlights behind you at night.
- A clean, properly angled mirror is essential — adjust it so you can see the full width of the rear window with minimal head movement.
How to adjust your rear view mirror correctly
Sit in the driver's seat in your normal driving position before adjusting the mirror. The mirror should show the full width of the rear window with just a small sliver of your car's sides visible on the edges. This positioning gives you the widest view of what is behind you.
Most rear view mirrors can be tilted up, down, left, or right using the mirror itself or a small lever or knob at the base. Adjust it so that when you look straight ahead, you can see the mirror without moving your eyes much. The goal is to check it quickly without losing focus on the road in front of you.
If your mirror has a manual dimmer, it is usually a small lever at the bottom. Pull it toward you to dim the mirror at night, which reduces the glare from headlights behind you. Some newer vehicles have automatic dimming mirrors that sense bright light and darken on their own.
When and how often to check your rear view mirror
You should glance at your rear view mirror every 5 to 10 seconds while driving. This rhythm helps you stay aware of traffic patterns and spot vehicles approaching from behind. Make these checks brief — a quick glance, not a stare — so you keep most of your attention on the road ahead.
Always check your rear view mirror before you brake, slow down, change lanes, or reverse. These moments are when a driver behind you needs to react, and knowing their position and speed helps you decide safely. For example, if you see a car approaching quickly from behind before you brake, you might ease off the accelerator gradually instead of braking hard, giving the driver behind you more time to react.
When reversing, the rear view mirror shows you what is directly behind the car, but it does not show the ground level close to the bumper. Many vehicles have blind spots near the rear bumper, so also turn your head to look over your shoulder and use your backup camera if your vehicle has one.
Understanding mirror blind spots
Even with a rear view mirror, there are areas behind your vehicle that you cannot see — these are called blind spots. The rear view mirror shows a straight line behind you, but it cannot show vehicles that are far to the left or right of that line. This is why you also need side mirrors and why turning your head to look over your shoulder is important before changing lanes.
The size of your blind spots depends on your vehicle's shape and size. Larger vehicles like trucks and SUVs have bigger blind spots than smaller cars. Taller vehicles may also have a higher rear view mirror position, which can change what the mirror shows. If you drive a vehicle with large blind spots, checking your side mirrors and looking over your shoulder becomes even more important.
Keeping your rear view mirror clean and functional
A dirty or smudged mirror reduces visibility and makes it harder to see what is behind you. Wipe your rear view mirror regularly with a soft cloth and glass cleaner, the same way you would clean a window. Do this when you clean your windshield or whenever you notice dust or fingerprints on the mirror.
If your mirror is cracked, fogged, or no longer reflects clearly, it should be replaced. A damaged mirror creates distorted images or blind spots that make driving less safe. Most auto parts stores sell replacement rear view mirrors, and installation is usually straightforward, though some vehicles may require professional help.
If your mirror has an automatic dimming feature and it stops working, the mirror may need a new battery or an electrical repair. Check your vehicle's manual for instructions, or take it to a mechanic or dealership to have it inspected.
How rear view mirrors differ in different vehicle types
Passenger cars typically have a standard rear view mirror that shows a clear, wide view of the rear window. Trucks and large SUVs often have smaller rear windows, which means the rear view mirror shows less area behind the vehicle. Some trucks have extended cab designs that make the rear window even smaller, requiring drivers to rely more on side mirrors and backup cameras.
Vehicles with tinted rear windows may make it harder to see through the rear view mirror, especially at night. If you drive a vehicle with heavy tinting, you may need to rely more on your side mirrors and backup camera. Some newer vehicles come with digital rear view mirrors — a small camera mounted on the back of the car that displays a video feed on a screen in place of a traditional mirror. These cameras often show a wider view than a standard mirror and work better in low light.
Frequently Asked Questions
Why do I see a red light in my rear view mirror at night?
The red light is the brake lights of a vehicle behind you. When the driver behind you presses the brake pedal, their brake lights turn on. This is a signal that they are slowing down. If you see brake lights approaching quickly, the vehicle behind you may be stopping suddenly, so be prepared to brake as well.
What does it mean when my rear view mirror is set to the night position?
The night position dims the mirror by reflecting light at a different angle, reducing the glare from headlights behind you. This makes it easier to see without being blinded by bright lights. Most rear view mirrors have a small lever or button at the bottom to switch between day and night modes.
Can I see everything behind my car with just the rear view mirror?
No. The rear view mirror shows what is directly behind you, but it does not show vehicles in your side blind spots or objects very close to the rear bumper. You need to use your side mirrors, turn your head to look over your shoulder, and use your backup camera if available to see the full picture before changing lanes or reversing.
Should I adjust my rear view mirror while driving?
No. Adjust your mirror before you start driving or when the vehicle is parked. Adjusting it while moving takes your attention off the road and increases the risk of an accident. If you need to adjust it during a drive, pull over safely first.