Müller-Lyer illusion

American  

[muhl-er-lahy-er, myoo-ler-, mil-er-, myl-uhr-lee-uhr] / ˈmʌl ərˈlaɪ ər, ˈmyu lər-, ˈmɪl ər-, ˈmül ərˈli ər /

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.

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Müller-Lyer illusion British  

/ 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

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Etymology

Origin of Müller-Lyer illusion

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

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.

From Slate

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

From Slate

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.

From Slate

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.

From Slate

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

From Slate