An optical illusion due to the physiologist Ewald Hering in 1861. The two horizontal lines are both straight, but they look as if they were bowed outwards. The distortion is produced by the lined pattern on the background, that simulates a perspective design, and creates a false impression of depth.
Hering Illusion
See also
Ehrenstein Illusion, Orbison's Illusion, Wundt IllusionThis entry contributed by Margherita Barile
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References
A Special Place. Optical Illusions. "Bowed or Straight?" http://aspecialplace.net/illusions/bowed_or_straight.htm.Cunningham, M. "The Illusions Pack." http://cayo.net/psy/DynoDemo/HernDemo.html.Landrigan, D. "A Hering Illusion Example." http://dragon.uml.edu/psych/hering.html.Nagoya Visual Illusion Experts Group. "Hering Illusion." http://humanities.lit.nagoya-u.ac.jp/~illusion/gallery/NVEG/standard/Hering01_e.html.National Science and Technology Centre, Australia. "Herring Illusion Explanation." http://www.questacon.edu.au/html/herring_illusion_explanation.html.Referenced on Wolfram|Alpha
Hering IllusionCite this as:
Barile, Margherita. "Hering Illusion." From MathWorld--A Wolfram Web Resource, created by Eric W. Weisstein. https://mathworld.wolfram.com/HeringIllusion.html