Judged: two independent readers; copy check clear.
horizontal–vertical illusion
horizontal–vertical illusion The horizontal–vertical illusion is a visual effect involving horizontal and vertical lines in which their perceived lengths are misestimated.
The horizontal–vertical illusion is a visual effect involving horizontal and vertical lines in which their perceived lengths are misestimated. In the source, it is used as a stimulus to compare how people judge line length in direct perception and in mental imagery.