Closeup magnifying glasses are great for fine work. I use them when mending a watch or soldering surface-mount components.
I've made a few pairs like this and find them easier to use than the commercially available ones. They're small enough to go in your pocket and very light to wear.
Start with two pairs of glasses from a pound shop (99c store).
Choose ones that are
- metal rimmed
- 3.5 dioptres (they should have a +3.5 sticker)
- with spring-hinges that stay open or closed
You will need
- two pairs of glasses
- fine pliers (preferably two)
- wire cutters
- sandpaper (nail/emery boards are good)
- soldering iron
Step 1: The Distant Lenses
Start with the glasses that are going to form the "distant" (objective) lenses.
Clip off the nose pads.
Sand the top of the rims. Even if they look like metal, they'll be covered in varnish.
Tin the top surfaces with solder.
Bend the bridge so the top surfaces of the rims touch. It's best to bend the wire by holding it with two pairs of pliers. If you put too much force on the rims of the glasses, they might break or the joint might come undone.
Solder the surfaces together. You'll need to apply enough heat to melt the solder but not so much you melt the plastic lenses.
The legs ("temples") of the glasses should be parallel.
In the picture above, the bridge of the glasses is wire and bends easily. If your glasses have a bridge made of cast alloy, you might just have to cut it. After you've soldered the tops of the rims together, you can reinforce the joint with brass or copper wire.
Step 2: The Legs
Remove the plastic earpieces (end tips) from the legs.
Decide how far away you want the distant lenses to be (about 75mm). Bend the legs outwards at right angles and curve them slightly so they fit over the tops of the near lenses.
Sand the legs and tin them with solder.
Sand the top of the rims of the near lenses and tin them.
Solder the legs of the distant glasses onto the tops of the rims of the near glasses.
Step 3: Finished
If you chose glasses with sprung hinges that stay open or closed, the distant lenses will flip up out of the way.
While you're wearing the glasses you can flip between fairly close and ultra closeup.