Eyeglasses were first invented in the late 13th century and have been employed to bring the world into focus ever since. While the general principle of convex and concave lenses has remained the same, the shape of the glasses has evolved considerably, and medieval spectacles bear little resemblance to their modern counterparts. Early eyeglasses had circular lenses and were generally connected by a wire arch over the nose. Ear holders, technically known as temple arms, were not invented until later, but you can add them if you prefer convenience over historical accuracy.
Instructions
things you’ll need:
Lathe and bit
Brass wire
Brass sheeting
Gas welding torch
Metal snips
1 Find the focal center of your glasses. This will be either the thinnest or thickest part of the glass, depending on whether yours are convex or concave. Measure how large a circle you can make around it before you reach the edge of the lens.
2 Remove one lens from its frame and carefully place it on a lathe. Cut it down to the circle you previously measured, using a sharp bit. Cut a small groove all the way around the outside of the lens’s circumference as well to hold the new wire frame. Repeat with the second lens.
3 Subtract 1mm from your diameter measurement and multiply it by Pi to calculate the circumference. Cut this length from brass wire and bend it into a circle. Weld the end closed and try to pop the frame over the lens to make sure it fits. It should sit snugly in the groove you cut earlier. Remove the lens and repeat for the second frame.
4 Add hinges to the outside edge of the frames, if you’re planning on having temple arms. Cut a rectangle approximately 7-by-10mm from brass sheeting, fold it into a U-shape the narrow way and weld it to the frame. Repeat for the other side.
5 Measure how far apart the lenses have to be, and cut wire long enough to connect them the way you planned earlier. Weld this into place between the two lens frames. Cut wires for the temple arms, if you want them, and bend them into shape, sticking one end down into the hinge loop and bending it off to hold it in place.
6 Clean your lenses and pop them back into the completed frame.
Tips & Warnings
You can use a jigsaw and cut the lenses by hand if you don’t have access to a lathe.