Uncle Tungsten: Memories of a Chemical Boyhood

by Oliver Sacks

It was also intriguing to reverse the pictures. One could easily do this with stereo photographs, but one could also do it by making a pseudoscope, with a short cardboard tube and mirrors, so that the apparent position of the eyes was reversed. This caused distant objects to look closer than nearby ones—a face, for instance, might look like a concave mask. But it produced an interesting rivalry or contradiction, for one’s knowledge, and every other visual cue, might be saying one thing, and the pseudoscopic images saying another, and one would see first one thing then another, as the brain alternated between different perceptual hypotheses.1 The other side to all of this, I came to realize—a sort of deconstruction or decomposition—could occur when I had migraines, in which there were often strange visual alterations. My sense of color might be briefly lost or altered; objects might look flat, like cutouts; or instead of seeing movement normally, I might see a series of flickering stills, as when Walter ran his film projector too slow. I might lose half of my visual field, with objects missing to one side, or faces bisected. I was terrified when I first got attacks like this—they started when I was four or five, before the war—but when I told my mother about them, she said she had similar attacks, and that they did no harm and lasted only a few minutes. With this, I started to look forward to my occasional attacks, wondering what might happen in the next one (no two were qu...