Hubert Airy’s 1870 illustration of his own scintillating scotoma, reproduced in P. W. Latham’s On Nervous or Sick-Headache (1873).

Claire L. Evans wrote a great article about the “scintillating scotoma”, a visual disturbance related to migraines. I had this a couple of times and it looks exactly as described. A terrifying but also extremely fascinating experience.

“Writing about these bizarre and horrifying perceptual phenomena, the late Oliver Sacks observed that migraines ‘show us how the brain-mind constructs ‘space’ and ‘time,’ by demonstrating what happens when space and time are broken, or unmade.”