The number of things that the human body and mind can achieve is astonishing. Take the case of Daniel Kish as a prime example. Daniel is blind, and yet you would not think so if you saw him walking around without any help.
The reason for this is very simple and it is all to do with echolocation. For those do not know, echolocation is what bats use in order to avoid flying into things, and it seems that Daniel has managed to perfect that technique for his own self.
As he walks around, Daniel makes a clicking sound with his tongue, and he then reads the sound waves that come back to him, as they change according to any objects that are ahead. From that, he is able to interpret the sound wave and can then move around without bumping into things.