Müller-Lyer illusion

[muhl-er-lahy-er, myoo-ler-, mil-er-, 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

Tucked into each of their suitcases was a booklet of drawings, including 12 examples of a prominent figure called the Müller-Lyer illusion.

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For one thing, lots of other animals see the Müller-Lyer illusion.

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There are versions of the Müller-Lyer illusion composed entirely out of curves, or just groups of dots; there’s even a version that uses people’s faces.

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Astoundingly, when shown the Müller-Lyer illusion—mere hours after recovering from their operations—they reported the top line as longer than the bottom line.

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Contemporary anthropologists have further popularized this view, arguing that “the Müller-Lyer illusion is a kind of culturally evolved by-product.”

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