Stephen Sackur speaks to photographer Giles Duley, who abandoned the world of celebrity, music and fashion photography to focus on stories of human suffering. In 2011 in Afghanistan, he lost both of his legs and an arm when he stepped on an improvised explosive device which detonated. Since then, he has defied the odds, not just surviving but returning to work and even revisiting Afghanistan. He is still a photographer, but does he now see the world through a different lens?