[SE]

The painter is looking, his face turned slightly and his head leaning towards one shoulder. He is staring at a point to which, even though it is invisible, we, the spectators, can easily assign an object, since it is we, ourselves, who are that point: our bodies, our faces, our eyes. The spectacle he is observing is thus doubly invisible: first, because it is not represented within the space of the painting, and, second, because it is situated precisely in that blind point, in that essential hiding-place into which our gaze disappears from ourselves at the moment of our actual looking. And yet, how could we fail to see that invisibility, there in front of our eyes, since it has its own perceptible equivalent, its sealed-in figure, in the painting itself?

-Michel Foucault

appearing in The Order of Things