We move on because david muir is back with a brand new report exploring the world and this time a stunning gift from an american doctor who traveled to either open ya and is giving people back their... See More
We move on because david muir is back with a brand new report exploring the world and this time a stunning gift from an american doctor who traveled to either open ya and is giving people back their sight. David was there for the moment they opened their eyes. It was extraordinary. As you know, 40 million people are blind around the world. For three out of four of them it is reversible. We get that care here in america but where we went this was nothing short of a miracle. Tonight the patches on those eyes come off. More than 8,000 miles away from his home in park city, utah, we land with dr. Jeffrey taben in either open ya. Little time to spare. Patience who are blind are waiting. Most of the people we see right here are waiting for you and the team? They are waiting for us. This is your doctor? Yes. Cataracts in both eyes. He can't see the blackboard? No. Reporter: Either open ya has been devastated by this disease. This is a line of people who have been screened by nurses. Reporter: Each of them with a tiny piece of tape bearing a number right above their eyes. A nurse asks this boy if he can see, his face blank. The doctor holds up his fingers. Suddenly another wave of villagers who have heard the doctor is here. This lady is totally blind, the one led by her son. Reporter: Inside, families who have led their loved ones here, pushing through the door get in. She doesn't see the shadow of the hand. Reporter: He quietly gets READY IN THE CORNER OF5x9c THIS ROOM With the instruments he'll use to perform a simple cataract procedure he perfected with a fellow doctor. WE'LL BE DOING ON On EVERY Seven or eight minutes. Reporter: We embed with this team for days. Every bed in the or has a patient currently being treated right now. You can see right here the next five or six patients waiting to go in. This is just the beginning. If you come around the corner they have to sign in and wait outside for the hope that they'll get to see the doctor today. In fact, come with me here. You can see this line. These are the patients who all hope to get in. In that crowd, number 245, and if you look closely, you can see that huge contact racket in her left eye. The doctor holdinggy she can't see it. We ask, does she think the doctor will fix it? Those young patients on the operating tables and with night fall comes the hope they'll be able to see the sun rise. Early the next morning, the lines form quickly. Just about ready to start taking off patches. Several of these people haven't been able to see in ten years. Reporter: He takes one of the first patches off, a farmer kisses his hand. Then the doctor with an order. Tell him to touch his nose. Yes, yes. THEN THE SOUNDS OF JOYw4 AND A Dance. Reporter: Another brought here by her son. Both of the patches come off. Beautiful. Reporter: We wondered about one more patient, that little girl in the gown. How many? Two! Reporter: Flashing a smile, she can see. Her dad told me she is headed to school. This is the lens that they replace in the eye after they take the cataract out. It costs $11. And it takes 7 minutes. So how can everyone help? For people at home who want to help out. Go to abcnews.Com, click on "world news" and remember it's $11. All of those people can see again. Wonderful. Thank you, david. And also in the news right
This transcript has been automatically generated and may not be 100% accurate.