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Game · The Body

Vanish

Close one eye, stare at the cross, and watch a dot pop clean out of existence. A hole in your vision you never knew was there.

Close one eye · stare at the + every fact sourced

  1. Sit about a forearm's length from the screen.
  2. Close your right eye.
  3. With your open eye, stare hard at the +, don't let your gaze drift to the dot.
  4. Slowly lean in and back. Somewhere around 30 to 40 cm, the ● simply pops out of existence.
What just happened?

The dot didn't fade or blur, it vanished completely, painted over with the background. Every eye has a blind spot where the optic nerve punches through the retina, leaving a patch with no light detectors at all, wide enough to hide several full moons. You never notice it because your other eye covers the gap, and your brain quietly fills the hole with whatever surrounds it. Hit “fill-in” and watch a broken line knit itself together across nothing. Edme Mariotte discovered this in the 1660s and amused the French court by making people's heads disappear.

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Our sources

// every fact this game reveals was checked before it went up

✓ The blind spot is the optic disc, where the optic nerve exits the retina; the nerve fibres all bundle through there, leaving no photoreceptors, so that patch of the retina detects no light at all. , Standard ophthalmology / visual neuroscience; Blind spot (vision)
✓ The blind spot spans roughly 5 to 7° of the visual field, because the full moon is only about 0.5° across, the blind spot is wide enough to hide several full moons. , Blind spot (vision); full moon ≈ 0.5° angular diameter (standard astronomy)
✓ You don't normally notice it because each eye's blind spot falls in a different place, so the other eye covers the gap; with one eye closed, the brain fills the hole by copying the surrounding colour and pattern across it, a dot vanishes and a line drawn through it looks continuous. , Blind spot (vision); perceptual filling-in research (Ramachandran & Gregory)
✓ The blind spot was discovered by Edme Mariotte in the 1660s; he presented it at the court of Louis XIV and reportedly demonstrated it by making people's heads appear to vanish. , Edme Mariotte (1620 to 1684), Pioneer of Neurophysiology; historical accounts