A few years ago, Don McPherson was wearing a pair of tinted glasses on a frisbee field. Don had designed them to protect the eyes of surgeons. Then his friend borrowed them, and saw something he'd never seen before. The color orange.
Don's friend was colorblind. And that moment led Don to figure out something that had stumped the medical world for centuries: How to help the colorblind see the rainbow.
Today on the show: Accidental inventions. Also, Planet Money's Kenny Malone discovers fuchsia.