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Mirror sunglasses

  1. Aug 4, 2007 #1


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    How do mirror sunglasses work? I used to think that they worked like "one way mirrors" but those are just half silvered glass - meaning that if you are standing in a bright room looking through it into a dark one you'll see your reflection but if you look from a dark room into a light room you can see through. But I noticed that with the mirrored sunglasses you can only see "out" no matter how the lighting is set up. So how do they work?
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  3. Aug 4, 2007 #2


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    They are as you say exactly like a darkened room. Rememebr that the 'room' behind them (between them and your eyes) is always likely to be darker than the room in front on them.
  4. Aug 4, 2007 #3


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    Yes, but even when I take the glasses off and hold them a few meters a way from me I can only see in one direction. How can that be?
  5. Aug 4, 2007 #4
    What would happen if you sandwiched a half-silvered mirror against a neutral density filter?

    From one side you would see a half-reflection which swamps a half-transmitted plus attenuated image. From the other side you would see a once-attenuated half-transmission superimposed on a twice-attenuated half-reflection. I don't know the construction of your particular sunglasses, but this would be a way of obtaining the effect you describe.
  6. Aug 4, 2007 #5


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    Thanks a lot, Froggie. I've been planning my supper for the past 2 hours, and your last post made me so dizzy that I can't eat. :grumpy:
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