Müller-Lyer illusion

[ muhl-er-lahy-er, myoo-ler-, mil-er-; German myl-uhr-lee-uhr ]

noun

1. a geometric illusion in which two lines of equal length appear unequal depending on whether angular lines forming arrowheads at each end point toward or away from each other.

Müller-Lyer illusion

/ ˈmuːləˈlaɪə /

noun

1. an optical illusion in which a line with inward pointing arrowheads is seen as longer than an equal line with outward pointing arrowheads

Word History and Origins

Origin of Müller-Lyer illusion¹

After Franz-Karl Müller-Lyer (1857–1916), German sociologist, who described the illusion in 1889

Word History and Origins

Origin of Müller-Lyer illusion¹

C19: named after Franz Müller-Lyer (1857–1916), German sociologist and psychiatrist

Example Sentences

The kids also fell for the Müller-Lyer illusion, a pair of lines with arrowheads on both ends; one set of arrowheads points outward, the other inward toward the line.

From Science Magazine

Martinez-Conde is willing to hazard a guess at how the Müller-Lyer illusion works.

From Science Magazine

Like Kahneman’s view of the universality of the Muller-Lyer illusion, the rational-agent model of human nature, which dominates economics, is based on a sampling error.

From Scientific American

The analogy to the Müller-Lyer illusion is close.

From Scientific American

If you have already encountered this image, however, you recognize it as the famous Müller-Lyer illusion.

From Scientific American