1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Mirror sunglasses

  1. Aug 4, 2007 #1


    User Avatar
    Gold Member

    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?
  2. jcsd
  3. Aug 4, 2007 #2


    User Avatar
    Science Advisor
    Homework Helper

    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


    User Avatar
    Gold Member

    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


    User Avatar
    Gold Member

    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:
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Mirror sunglasses
  1. A floating mirror. (Replies: 4)

  2. The Mirror Question (Replies: 4)