Here is what you need:
1.) One Sugru pack (you choose your favorite color)
2.) One LED (I prefer bright white because of illuminance)
3.) 3 pieces of 1V batteries (total 3 V)
4.) One simple and small enough circuit breaker.
Procedure is pretty simple especially if you can get some already made light pack from cigarette ligher or keychain as you can see in photos.
So you just open Sugru, make the shape that will fit your "hardware" put it all around it and in the end make some wide hook so that you can attach it on your glasses after Sugru solidifies.
In case you don't wear glasses you can rearrange the hook into shape that can be attached at the top of your ear.
We tested it in totally dark place with no light in there and result was great. You can see it in photos.
Good luck and have fun :D