I have a set of loupes from Harbor Freight. You are supposed to be able to hold them with the muscles around your eye socket. While needing both hands recently to work on some fine wires, I decided I needed a way to hang the loupe on my eyeglasses.
Step 1: What is needed
I needed some 16 gauge steel wire and a small piece of heat shrink tubing. I also needed a needle nose pliers, a heat gun, and a ruler.