I realized that this man understands how to use a vantage point in a drawing. On the one hand this is extraordinary. So you might expect it to be the last thing blind people would ever come up with on their own. And that's not something inherently visual. For the sighted vision simply discovers the same things about the world that touch reveals to the blind.
Blind people understand a lot about the directions of objects in the world.
They often have to judge where they are with respect to objects as they move around in the world and change their vantage points. A blind person who didn't have a rich idea about the way the world's laid out, and how things change around them as they move through it, would be permanently chair-bound. And that's something Kennedy is keen to help prevent. Kennedy's work with blind people started as an offshoot of his work on pictures by and for the sighted. But years of working with the blind and spelling out how rich their vision really is have made him something of an activist.