The Zöllner illusion is a classic optical illusion named after its discoverer, German astrophysicist Johann Karl Friedrich Zöllner. In the illusion, parallel black lines seem to be unparallel because shorter lines are added angling away from to the longer lines. These angled lines help to create the impression that one end of the longer lines is nearer to us than the other end. This illusion was used to beautiful effect by supertalented Swedish designer Martin Frostner in his catalog design for Carsten Holler, One Day One Day. See also the Orbison illusion, the Müller-Lyer illusion, the Poggendorff illusion, and the Hering illusion.