A rear view mirror is the interior mirror mounted at the top center of a car’s windshield that gives the driver a clear view of traffic behind the vehicle.
Whether you’re learning to drive or considering an upgrade, understanding the rear view mirror starts with what it actually does. This interior mirror lets you monitor vehicles, pedestrians, and obstacles behind you without turning around — supporting lane changes, merging, reversing, and everyday situational awareness on the road.
The Definition and Location of a Rear View Mirror
A rear view mirror is defined in automotive standards as any device intended to give a clear view to the rear. This broad definition comes from both UN/ECE Regulation No. 81 and India’s BIS mirror specifications, which treat the device by its function rather than its exact shape or size.
In a standard passenger car, you’ll find this interior mirror mounted at the top center of the windshield, inside the cabin. It’s distinct from the side mirrors mounted on the doors, which cover different fields of view. The interior rear view mirror shows what’s directly behind you through the rear window.
Types of Rear View Mirrors
Modern vehicles offer several mirror options, each with its own strengths. Here’s what you’ll encounter:
- Standard glass mirror — the traditional reflective surface found in most cars.
- Auto-dimming mirror — automatically reduces glare from headlights behind you at night.
- Rear camera mirror — displays a live video feed from a rear-mounted camera instead of (or alongside) reflected light. Nissan’s Intelligent Rearview Mirror, for example, uses a built-in LCD monitor to show rearward video.
- Streaming rearview mirror — a larger display-based mirror. The Metra Electronics 9″ Live View Streaming Rearview Mirror offers a 9.66″ 1280×320 display with a 1080P camera.
If you’re shopping for a replacement or upgrade, a roundup of the best universal rearview mirror options can help you compare features and find one that fits your vehicle.
How to Adjust and Use Your Rear View Mirror Properly
Correct adjustment takes seconds and dramatically improves visibility. Position the center mirror so you can see the full rear windshield without moving your head or body. You should be able to glance up and instantly see what’s behind you.
Use the mirror before every lane change, merge, or brake. Check for vehicles approaching from behind, then confirm with side mirrors and a quick head check for blind spots. The interior mirror alone won’t cover everything.
At night, many drivers tilt the mirror to its glare-reduction position or rely on an auto-dimming feature. The interior mirror helps with judging distance and preventing glare, making night driving significantly safer.
Common Mistakes to Avoid
- Confusing it with side mirrors — each serves a different field of view; you need all three.
- Poor positioning — setting the mirror too high or low misses the rear window entirely.
- Ignoring blind spots — the rear view mirror has limits; side mirrors and head checks are still essential.
- Installing incompatible aftermarket mirrors — larger, tinted, or camera-based mirrors can block your forward view or conflict with vehicle safety requirements.
U.S. Safety Standards and Compliance
In the United States, the federal rear-vision standard is FMVSS 111, codified at 49 CFR §571.111. This regulation governs the required field of view for vehicles sold in the U.S. Any replacement mirror should not interfere with that required field of view or safety compliance.
International standards offer useful benchmarks for mirror quality. UN/ECE Regulation No. 81, for example, specifies that motorcycle rear-view mirror reflecting surfaces be spherically convex with curvature radii between 1,000 mm and 1,500 mm. For passenger cars, the Indian standard IS 14210 (1994) recommends circular mirror diameters between 90 mm and 150 mm. When choosing an aftermarket mirror, look for products that meet recognized quality and safety specifications.
References & Sources
- Wikipedia. “Rearview Mirror.” Overview of rearview mirror types, history, and functions.
- U.S. Government Publishing Office. “49 CFR §571.111 — Federal Motor Vehicle Safety Standard No. 111; Rearview Mirrors.” The U.S. federal rear-vision standard for vehicles.
- European Union. “UN/ECE Regulation No. 81 — Rear-View Mirrors for Two-Wheeled Vehicles.” International specifications for rear-view mirror dimensions and curvature.
FAQs
What is the difference between a rear view mirror and a side mirror?
A rear view mirror is the interior mirror mounted at the top center of the windshield, showing what’s directly behind the vehicle through the rear window. Side mirrors are mounted on the doors and cover the areas beside and slightly behind the car. All three work together for complete rearward visibility.
Why does my rear view mirror have a tab or lever at the bottom?
That’s the manual night position. Flipping the tab tilts the mirror slightly, reducing glare from headlights behind you at night. It doesn’t change the mirror’s angle permanently — it just shifts the reflective surface so bright lights appear dimmer while you still see traffic behind you.
Are aftermarket rear view mirrors legal in the U.S.?
Generally yes, but the mirror must not interfere with the field of view required by FMVSS 111. Larger, tinted, or camera-based mirrors may affect visibility or brightness. Check that the mirror mounts securely to your original attachment point and doesn’t block your forward view. When in doubt, consult a professional installer.