He's taking a really narrow view of the word "visualize", though. This morning, I was wide awake in bed, thinking about some documents I would have to write when I got up. As my hands lay on top of the bedspread, my fingers were twitching, just as though I was typing up the document I was imagining in my mind. I would say I was visualizing myself typing that document, even though I don't have any vision. In the same way, companies and organizations have vision statements. It has nothing to do with sight; it's about imagining change. And yes, blind people can mentally imagine doing things, or changing things, the same way sighted people might.