Ebola infests a survivor's eye, and turns it green

Dr. Ian Crozier caught Ebola last year, but survived and seemed Ebola-free -- until scientists discovered his left eye still harbored a mass of infection, so bad it turned the eye green.

It's a fascinating, if unsettling story -- because it shows that we still have a ton to learn about how Ebola infects humans, and how it might remain, lurking around, for quite a long time.