One day I was thinking, glasses are used to see right? What about seeing in the dark? That would be cool!! So I decided to design a low powered light perfect for late night reading and for maneuvering around a dark house so you don't have to wary about waking anyone up!
After you printed the case you must insert the batteries. First you have to solder a small segment of your wire to a small piece of a metal sheet. Next insert this onto the bottom of the case. Now you can insert the batteries!
First I crimped a small sheet of metal to fill in any extra space between the led(s) and the batteries. Then soldered the crimped piece of metal to the led(s) and placed it in. Using electrical tape I covered any other connections so that I wouldn't short the circuit. Than I glued the led(s) onto the front.
The switch is easy all you have to do is to connect the rest of the two wires together, soldering one to the middle lead and the other wire to a lead on the side. When you have made sure that works glue that switch onto the side of the case!
Have a look here
for more details.