How is it called?

Hi,

You know those windows which becomes one way when its hit by light? it’s like a one way window which changes by where it is hit by light so in the morning time, when there is sun, inside the house you will see the outside but from the outside you won’t see the inside of the house. at evening it changes. What is the professional name for these windows? Thanks.

By Williams | 08/29/2009 12:38 PM