If you’ve got a spare LCD monitor lying around and you’re comfortable enough to disassemble electronics, you can turn it into a pretty cool privacy monitor. An electrical engineer who met the aforementioned requirements recently turned the LCD monitor into a “privacy monitor” that can only be seen with the use of special glasses. He disassembled the monitor, took apart its plastic frame, cut out the polarized film with an utility knife, and removed the film adhesive from the glass panel.
He then reassembled the monitor and fitted a pair of theater 3D glasses with the film that was removed from the monitor. Viola! A privacy monitor was created. Regardless of what is being shown on the monitor, people without the special glasses will only be able to see a blank white screen. This is probably one of the coolest ways I’ve ever seen a monitor being reused. Head over to Instructables for more detailed instructions.