DIY Magnetic Eyeglasses/Badge Holder

Similar things sell for $10-$20 depending on the extent to which they're decorated. I made this for less than $3 and the only thing I actually had to buy new was the magnet. When I use my creation as a badge holder, I often decorate it with a metal pin-badge. The magnet holds both the washer and the pin in place without making holes in my clothing and I can change the pin to suit the occasion.