Zöllner Illusion

The Zöllner Illusion is a visual effect where parallel lines appear to incline or diverge because of short crosshatched lines crossing them at an angle. These diagonal markings distort the viewer’s perception, making straight lines seem tilted, even though they are perfectly parallel. The illusion occurs because the brain interprets the intersecting lines’ angles as cues for depth and orientation, tricking us into perceiving a bend or tilt where none exists. It demonstrates how our visual system processes angles and line intersections, sometimes leading to misinterpretations of spatial relationships.