Sunglasses that can change color.
Hey, recently I come to know about some sunglasses that can change colors. The typical material which will use in color-changing glasses is called a photo chronic film, or a sheet of polymers that change color when light hits them. Biggest benefit of this material is that it can change colors as quickly as electricity passes through it - which is virtually instantaneously.
So these sunglasses can be very handy for security personals.