There is a hole in your vision
Each eye has a blind spot where the optic nerve leaves the retina. There are no photoreceptors there. You do not see the hole.
Established2 min read
Mariotte found it in 1668 by the courtier’s experiment: close one eye, fix the other, and a mark at arm’s length disappears. The optic disc is nasal to the fovea, so the blind spot lies outward of wherever you are looking. Two eyes cover each other’s gaps. One eye, the cortex fills from the surround.
The fill is not a photograph of what was there. It is a guess, usually a continuation of colour and texture. Put a pattern across the spot and the pattern completes. The hole is anatomical. The seamlessness is a story.
Caveats
- The fill fails for fine detail. A small object can still vanish if you place it carefully.
Sources
- 1Mariotte E.. Nouvelle découverte touchant la veüe. report to the Paris Academy, the blind spot, 1668.