The instructable shows how to adapt an ordinary eye loupe to an illuminated LED eye loupe. After I made one, I was surprised at how much better the magnified objects look due to the illumination.
Step 1: Components and Tools
1. SMD White LEDs PLCC package - 8 numbers
2. SMD Resistors 100 Ohm 1206 or 0805 size: 8 numbers
3. copper clad board (stock PCB), cut an annular shape (see the next step for the dimensions)
4. ordinary eye loupe
5. Battery holder (4xAA battery holder)
1. Multistrand connecting wire with plastic insulation, 2 colors - 1 feet each
2. Instant glue
3. Solder iron and wire
4. wire cutter
Step 2: Make the PCB
Measure the diameter of the lens and the diameter of the rim of the loupe. Let A be the diameter of the lens and B the diameter of the rim. The inner diamater (ID) Of the annular PCB should be equal to A and the outer diameter of the annular PCB should be equal to B.
An eagle brd file for our annular PCB can be downloaded from this instructable and used as is or modified for your particular loupe dimensions.
We used a Modela milling machine to cut the PCB, but with a bit of effort and patience, you can actually do it manually with a drill machine and dremel tool to separate the copper in two circular concentric bands.