Silvio Velo has been blind since birth, but you wouldn't know it watching him thread a football through an opponent's legs, pick it up on the other side and fire it home for a goal. Velo, who has been called the "blind Lionel Messi," is the captain of Argentina's visually impaired football team, the Murcielagos (Bats), who are hoping to win gold at the Rio de Janeiro Paralympics in August.