What is the Müller-Lyer illusion?

The Müller-Lyer illusion is characterized by the perception of two lines of equal length appearing to be of different lengths because of the addition of arrow-like figures at their ends. This illusion highlights how contextual cues can affect our visual perception. The outward or inward orientation of the arrowheads creates a misleading context, leading our brains to interpret the length of the lines differently, despite them being equal in actual length. This phenomenon emphasizes the role of perception in interpreting visual information and illustrates the complexities of how our visual system processes spatial relationships and depth cues.

Other choices address various aspects of visual perception, such as color contrast and perspective, but they do not specifically describe the Müller-Lyer illusion, which is fundamentally about the misperception of line length caused by external markers.