Speaker 1: Welcome to brain Stuff from how stuff Works dot com
Speaker 1: where smart Happens. Hi, I'm Marshall Brain. Have you ever
Speaker 1: used the glare resistance setting on your car's rear view
Speaker 1: mirror and wondered what's going on? How can the same
Speaker 1: piece of glass have two different amounts of reflection. If
Speaker 1: you stand in front of a normal window in your
Speaker 1: house at night, inside the house with the indoor lights on,
Speaker 1: you'll be able to see your reflection in the glass
Speaker 1: quite clearly. A car's mirror takes advantage of that same effect.
Speaker 1: The mirror in your car isn't ground flat. The front
Speaker 1: glass surfaces at an angle to the back mirrored surface,
Speaker 1: so if you were to look at this mirror out
Speaker 1: of its casing, it would be wedge shaped, with the
Speaker 1: thicker edge up at the top. When you flip the mirror,
Speaker 1: the back mirrorred surface usually points towards the dark ceiling,
Speaker 1: so you don't see that image. What you see instead
Speaker 1: is the image reflecting off the front of the glass,
Speaker 1: and this is much dimmer than the pure reflected image,
Speaker 1: so it doesn't hurt your eyes. Be sure to check
Speaker 1: out our new video podcast, Stuff from the Future. Join
Speaker 1: how Stuff Work staff as we explore the most promising
Speaker 1: and perplexing possibilities of tomorrow. The House Stuff Works iPhone
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