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We've all seen that label on our passenger side mirrors that says, "Objects in mirror are closer than they appear." Why is this? Further, why does it only apply to the passenger side mirror, and not the driver-side or rear-view mirrors?

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""We've all seen that label on our passenger side mirrors that says,"" Our? Yours maybe, in Europe You will never see such a label (till now) :=( –  Georg Jul 27 '11 at 15:48
    
Eh, just kind of assumed, never been to Europe lol. –  MGZero Jul 27 '11 at 17:52
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2 Answers

up vote 11 down vote accepted

The mirror is made convex in order to provide a wider field of view. Thus, the objects in it appear smaller than on a flat mirror, and your brain infers they should be further away.

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So only the passenger mirror is convex, then? –  MGZero Jul 27 '11 at 13:53
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I don't know, I guess it may depend on the car model. But the passenger mirror is probably the only one that is so far from the driver's eyes that it really needs to be convex in order to provide a decent field of view. –  Edgar Bonet Jul 27 '11 at 14:20
    
As far as I know, the passenger mirror is convex and the driver-side mirror is flat in every modern car. I'm not sure if there are regional differences. I am in the north-eastern US. –  Colin K Jul 27 '11 at 15:50
    
In my car (Germany, Opel) both mirrors are slightly convex. The mirror on the driver side has a more complex form, the outermost part (about a fifth of the mirror) is stronger konvex. This results in a standard view plus a concentrated view of the lane feft to me. (From where a faster car can approach) –  Georg Jul 27 '11 at 16:30
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The reason only the passenger mirror is convex is because you are farther away from it. The angular view provided by farther mirror of the same physical size produces a similarly smaller reflected field of view. The convex mirror provides a larger field of view- one that should be comparable to the closer drivers mirror.

You could instead mount a much bigger mirror on the passenger side and get the same field of view if you prefer a flat mirror.

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