Forty million people worldwide live in total darkness and 90 percent of them live in the developing world.
However, three out of four such cases are reversible, according to Dr. Geoffrey Tabin, director of the division of international ophthalmology at the John A. Moran Eye Center.
Tabin spends a large part of the year traveling around the world restoring sight to thousands of people with cataract blindness.
ABC News joined him on a recent trip 8,000 miles from Tabin’s home in Park City, Utah, to Ethiopia, which has one of the highest rates of blindness in the world.
When the ABC News team arrived at the Quiha Zonal Hospital in the remote city of Mekelle, Ethiopia, there were already hundreds of patients waiting for Tabin.
For the patients, the journey to Mekelle was a pilgrimage of sorts.
They came from cities, villages and small farming communities throughout Ethiopia to see Tabin. Getting to the clinic was no small feat considering their condition. Many had traveled for days.
Cataract blindness is an epidemic in Ethiopia, and doctors point to poverty, poor nutrition, genetics and the scorching sun as reasons for the devastating numbers. Read more