Dr. Ian Crozier was diagnosed with Ebola in September 2014 while working to combat the deadly disease in Sierra Leone.
Crozier was subsequently cared for at Emory University Hospital in Atlanta, Georgia, for more than 40 days.
He was released in October 2014 after Ebola was no longer found in his blood samples.
Crozier told the World Affairs Council in December 2014 that he was interested in returning overseas to help fight the Ebola virus (video below).
However, he began experiencing some inflammation, high blood pressure and difficulty with vision in one of his eyes.
Dr. Steven Yeh, an ophthalmologist at Emory, drained fluid out of Crozier's eye and tested it for Ebola, noted the Associated Press.
According to Live Science, the fluid "between the eye's outer covering and the lens" tested positive for Ebola, but Crozier's blood, tears and tissue did not.
This positive testing was the first time that Ebola was found in the eyes of someone who tested negative for Ebola in their blood.
Yeh claims that Crozier is improving, but has not completely recovered his full vision yet.
Dr. Jay Varkey, who works at Emory, added that medical personnel who treated Crazier wore protective outfits and checked themselves for weeks for signs of Ebola.