Some blind people can see using sound. They echolocate. When they do this, their visual cortex responds to sounds like it normally would for sight. Through stories of blind individuals who can ride bikes using sound and babies who learn to 'see' using specially designed glasses, this article takes us deep into questions about the nature of perception itself. What if seeing isn't really about having working eyes at all? The answer might just change how you think about what it means to see.
