Rebecca Davis

One of the most important medical advances may also be the simplest: hand-washing. It's the best defense against spreading disease. And its power was discovered long before anyone knew about germs.

It was June. Joshua Mugele, an American ER doc, was working at a Liberian hospital when the first Ebola patient came in. No one was prepared. Yet the terrified staff took great risks to treat the man.

If you think that an artificial eye looks like a big glass marble, you're not alone. And you're wrong. We visit the people who made a prosthetic eye for a 5-year-old boy who lost an eye to cancer.