Incredible optical illusions in design

Mach strips

Placing shades of one color was a common trend in the era of flat design. You may have noticed fake shadows, appearing between the edges of each contrasting shade. This illusion is known as Mach stripes (a phenomenon named after the psychologist Ernst Mach). No shadows have been added to the image, just so perceived by our eyes!

The technical explanation for this effect is related to lateral inhibition, which means that dark areas look wrong even darker, and light - mistakenly looks even lighter.

Although this effect is quite insignificant for the world of visual design, the influence of Mach stripes can be a real obstacle for dentists. X-rays of the teeth generate shades of gray, which are used to analyze deviations. Mach strips may cause a false-positive diagnosis 🙂

Hering’s illusion

Have you ever come across a logo that contains very thin lines or a background image with tiny dots that seem to move or pulsate while scrolling? And what about watching a video that has wavy lines in the background, which also do not seem to stand in place? This is due to an effect called the Moire pattern: two grid patterns overlap, creating an erroneous impression of movement.