Now you can secretly look behind you and no one will notice :P this is a good project if you are wanting to teach somebody about how lights works and ...
This project allows you to look behind you secretively BUT it also lets you see forward as well, so if you want to develop this simple project you can have two mirrors and stick them on an old pair of glasses to create spy glasses
What you'll need is: a small mirror (maybe from an old, unused compact mirror) and something to scratch the back off with (I used a penny)
Step 1: Find a small mirror
Find a small mirror mine was from an old compact mirror