They have basic IR "filters" which are used to reduce IR light, but they don't totally block it, which is why you can see a purple light coming from TV remotes

They have basic IR "filters" which are used to reduce IR light, but they don't totally block it, which is why you can see a purple light coming from TV remotes and such [0] 0: http://www.wikihow.com/images/6/60/Check-if-a-Remote-Control-is-Transmitting-an-Infrared-Signal-Step-6.jpg http://www.wikihow.com/images/6/60/Check-if-a-Remote-Control...