Zöllner illusion
psychology
Quick Summary
Examples of optical illusions.
Figure 2: Examples of optical illusions. (A) Cube changes orientation. (B) Lines are equal in length. (C) Lines covered by rectangles are straight. (D) All long lines are parallel. (E) Circles are equal in size. (F) Horizontal lines are parallel. (G) Black dots are equal in size. (H) Tops of circles are on a straight line.
The Zöllner illusion is a visual illusion that causes parallel lines to appear non-parallel. This occurs when the lines are intersected by a series of short, diagonal lines. The illusion is named after Johann K. F. Zöllner, a German physicist who described it in 1860.1
An illusion is a misinterpretation of sensory stimuli, where perception contradicts objective reality. The Zöllner illusion is a type of perceiver-distortion illusion, where the brain's processing of visual information leads to a false impression.2
Summary created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
2 Britannica Sources
Ask Britannica AI about this topic
Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.