Eighteen-year-old Ker Deng is exploring the streets of Manhattan, learning to use his cane to guide him.
As a child in Sudan, he was kidnapped, tortured and blinded by his slave master.
"He abused us all the time" he said in his native language. "One time he beat me and hung me upside down and rubbed peppers into my eyes."
But Ker was recently brought to the United States and has just begun vision rehabilitation training at Lighthouse International, a nonprofit organization in Manhattan that helps the visually impaired get their lives back.
"They can work and have children and date and go to school and accomplish whatever they want to do independently and also safely," said Merrie Balka, vision rehabilitation therapist at Lighthouse International.
As part of the training, Merrie Balka is teaching Ker how to use a cane and how to cross the busy streets of Manhattan.
He's using the constant contact technique, keeping the cane tip on the sidewalk at all times to feel for cracks, grates and level changes. First, he has to find the intersection.
Then he listens for the traffic pattern.
When he hears the parallel traffic start to go, he goes.
The same techniques can help the visually impaired navigate the subway stairs and the gap between the platform and the train.
But everything is a potential obstacle, the plant holder, the stroller, the woman glued to her cell phone.
Although Ker worries about getting hit or running into a car, it has never happened.
Ker says he sees the world through the cane and he listens for everything, people, cars and bikes going by.