The highway stretches dark ahead, and your headlights carve a tunnel through the night. A car pulls up behind with LED beams so bright they flood your rearview mirror with white light. The glare burns into your peripheral vision and makes the road ahead harder to see. Most drivers don’t know their rearview mirror has a built-in fix for headlight glare. Plenty of driving advice covers headlights and windshields, but the best tips for night visibility start right above your dashboard.

Man’s hand presses adjusting rearview mirror dimming. Selective focus.
Flip the small tab under your rearview mirror to instantly dim glare from bright headlights.
Image credit: Shutterstock
How The Dimming Works
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The tab changes the angle of your mirror when you flip it. Some tabs push and pull while others flip up and down, but all make a subtle click when moved. That click tells you the mirror has tilted to its night position. The change looks subtle if no bright lights are hitting the mirror, so test it with headlights behind you to see the difference clearly.

The view behind you should stay visible, but it looks much darker. This happens because rearview mirrors use wedge-shaped glass with a reflective coating on the back surface. In the day position, light bounces off that back surface to give you a bright, clear reflection. Flip to night position, and the mirror tilts so the reflection comes from the weaker front surface instead.