Rear View Mirrors
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
Nathan A. Unterman
The front surface of the glass is not parallel to the back (silvered) surface.
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Update: June 2012