Poggendorff Illusion

The Poggendorff illusion is named after Johann Poggendorff who identified it in 1860. It is a geometrical-optical illusion which involves the misperception of the position of a segment of a transverse line, which has been interrupted by the contour of an intervening structure (a rectangle).


Howe, Catherine Q., Yang, Zhiyong, Purves, Dale (2005), The Poggendorff Illusion Explained by Natural Scene Geometry (PDF).

See list of more illusions.