An optical illusion in which the orientation of arrowheads makes one line segment look longer than another. In the above figure, the line segments on the left and right are of equal length in both cases.
Müller-Lyer Illusion
See also
Illusion, Poggendorff Illusion, Ponzo's Illusion, Vertical-Horizontal IllusionExplore with Wolfram|Alpha
References
Fineman, M. The Nature of Visual Illusion. New York: Dover, p. 153, 1996.Luckiesh, M. Visual Illusions: Their Causes, Characteristics & Applications. New York: Dover, p. 93, 1965.Referenced on Wolfram|Alpha
Müller-Lyer IllusionCite this as:
Weisstein, Eric W. "Müller-Lyer Illusion." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/Mueller-LyerIllusion.html