A team of international brain researchers recently produced some unbelievable footage: A completely blind man walking down a littered hallway, apparently cognizant of the obstacles before him and avoiding them all. For years, scientists have quarreled over the legitimacy of "blindsight." Now, it seems undeniable - but what will be the consequences? We're joined by Richard Held, who pioneered blindsight research in the 1970s, and Rob Stein of the Washington Post.

Watch video footage here, hosted by Professor Beatrice de Gelder, a member of the research team.