There's a strong misconception that being blind makes it more difficult to play piano- this is simply not true. We know that other senses become stronger when you lose sight or hearing, and, in this case, if he trained from an early age, his spatial awareness could make it far easier to play piano then for us sighted people who rely on our vision to see where the keys are. Actually, in a sense, training to play piano WITH vision is arguably more difficult, aside from obvious hinderances like interpreting sheet music and communicating with others (conductors, orchestra, etc.).