I DIDN’T KNOW THAT

Question: How does a glare-resistant rear-view mirror in a car work?

Answer: The mirror is wedge-shaped and actually has two reflective surfaces, the normal silvered mirror on the back and the glass front of the wedge. When the mirror is in its normal position, objects behind the car are reflected off the silvered surface.

When the mirror is flipped up, the silvered surface reflects light toward the car’s ceiling and the driver sees only the dim image reflected off the front of the glass wedge. The latter effect is just like the image you see in a window when it is dark outside.