The story
Named after Johann Christian Poggendorff, journal editor who discovered the effect in figures submitted by Johann Karl Friedrich Zöllner in 1860.
Etymology from Wiktionary, CC BY-SA 4.0.
Poggendorff illusion
Today it means: An optical illusion involving the misperception of the position of one segment of a transverse line that has been interrupted by the contour of an intervening structure. Full definition →