Visit you local pharmacy or hardware store to pick up a plastic pipe coupling that has an approximately 2-inch diameter. Also purchase a similarly sized magnifying glass, adjustable sunglasses strap, key rings and thread.
Remove the handle from the magnifying glass so that you are left with only the circular glass in your hand.
Put superglue around the rim of the pipe and press down the magnifying glass over the rim, sealing the opening and holding for 30 seconds. It is OK if the magnifying glass diameter is larger than the pipe, resembling a mushroom, but the better fit is that both pieces are approximately 2 inches in diameter with the magnifying glass being only slightly larger.
Wrap your thread multiple times around the center of your pipe and tie a strong not. The direction of the thread should be parallel to the magnifying glass.
Attach two key rings to the left and right side of the pipe by using a needle or your fingernails to slightly lift the strings from off the pipe and slide the key rings on. Then remove the needles.
Loop your sunglasses strap through the two key rings. This will go around your head and adjust to fit, with the eyepiece over your eye.