Michael: Sometimes when I've been driving with you, you'll tell me to make a right turn at the next corner, or to park in the lot just beyond the restaurant. And you seem to do fine walking around your neighborhood, or even other neighborhoods, without a cane--negotiating curbs and tricycle-littered sidewalks pretty well. What sort of visual information are you getting as you move through the world?

Joel: It's like looking out through a translucent plastic shower curtain that is becoming very steamed up. Just as, from the shower, you can still see enough to know that the sink and the toilet, even if blurry and half obscured, are still there, so I can more or less see my way around. One helpful thing is that, because my extreme peripheral vision so far remains fairly clear in all directions, I can at least catch a glimpse of what I don't look at directly, like those curbs and trikes. When I start tripping over them, that's when the tip of my white cane will finally touch down and start scanning the pavement.

Michael: As you walk, is your attention pretty narrowly focused, like on the one or two feet of sidewalk in front of your shoes? Or are you "scanning" a lot of the world around and in front of you?

Joel: I walk erect and look straight ahead, scanning from side to side every few seconds to let the remaining vision in each eye's far peripheral field catch a glimpse of anything I know I may be missing in the blotchy view right in front of me. Out of the corner of my eye, as we say.

Take a walk with Joel

Michael: I would think that, in walking through familiar territory, you would be working from a mental map drawn up in earlier, more visually lucid, times--constantly connecting new visual information with what you remember of past views of the same place. How important is your memory in getting around?