Ye Olde Zöllner Lines
Stare at the pattern for a minimum of thirty seconds. The effect intensifies the longer you gaze. So gaze!
How It Works
German astrophysicist Johann Karl Friedrich Zöllner (1834 – 1882) first experienced this visual high in a piece of dressmaking fabric. The numerous repeated lines in the herringbone pattern on the fabric aligned at perfect 45-degree angles, and appeared to converge and diverge after a while, twisting and turning into a cosmically distorted nest of psychedelic spindles.
There are numerous theories about how this visual high works, or rather, why our visual system has problems processing the Zöllner Lines accurately. One theory is that because the shorter lines are at such an angle to the longer lines, our brain processes the longer lines as nearer to us. This gives the Zöllner lines an impression of depth. Another theory is that the brain has a tendency to overestimate angles that are less than 90 degrees (acute angles). At the same time, the brain has a tendency to underestimate angles over 90 degrees but less than 180 degrees (obtuse angles). This all makes the longer line and the shorter lines crossing it appear as though they are more perpendicular to one another than they really are. The brain then interprets these lines as slanted.
Though the herringbone pattern has been in and out fashion over the last 150 years, this freakishly simple illusion remains and continues to stump us.