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Name: Dave
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Age: 13
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Glare from headlights can create serious vision problems for night drivers. There is a feature of the rear view mirror that can be used to prevent the glare of the headlights from reaching the driver's eyes. How does it work?

During daytime viewing, the rear view mirror is set so that the reflection is from the back, silvered part of the mirror. At night, the mirror is tilted so that the reflection of the headlights behind you only hit the front glass surface of the mirror and reflects from it. Since this surface is only 5% reflective, the glare is significantly reduced. If you look at the ceiling while someone else is driving using the night setting of the mirror at night, you see a bright reflection from the car behind you.

Since the night setting of the rear view mirror is a reflection from the surface of the mirror's glass, such an arrangement would not work for oncoming traffic.

Nathan A. Unterman

The front surface of the glass is not parallel to the back (silvered) surface.

Tim Mooney

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