Let’s see. What do we know about sight?

What you see is present right now, because of the speed of light and because it goes in straight lines. You can use it to build a dependable internal 3d model of your surroundings.

Um. You only see what is meaningful. That is to say, you only see what is close to you… but I want to avoid terms that imply things like physical distance, because we want to use these ideas where there is no physical distance.

So let’s just say that if things are close to each other, they can affect each other more. And if things are far away, it doesn’t matter what each one does, because they can’t touch. That’s just physics for you. So short distance is meaningful: you only see what is meaningful.

What else. You can see where other people are looking and react to that, but we’ll ignore that for the moment.

Another thing. There is such a thing as peripheral vision, which is used as an automatic early warning system or or background information. When something happens, we orient towards it. Since we can move in the same world as we see in, walking or moving should be considered a way of responding to peripheral vision too, although a bit slower than moving the pupils.

Moving through the world of vision is called active vision by the way. You get more information out as you move past and through things. Try standing underneath a tree and looking up through it, rocking side to side. As you move, it pops into 3d.

Lastly, sight only does surface. Obviously. But it’s a very abstract sense. We only see the cover, enough for us to recognise an object. We get excited about these names and surfaces we see, and that’s the spectacle: the obsession with the surface beyond all else.

Given all of this: what is sight really?

To us, to this brain here, sight is an internal model of everything meaningful in this location, with 3d structure cleverly deduced. I can imagine what’s nearby in 3d, and give you the names of everything further away. And once I’ve moved through the world, I have a better picture of it in my head. That’s sight.

Matt Webb, S&W, posted and presented on 2006-06-01