Optic Illusion

Optic Illusion gathers 72 optical illusions into a small museum of visual perception. Every one comes with a direct explanation of what your eyes and brain are doing to cause the effect — 33 interactive, 14 animated, written for curious humans.

What's inside

• Motion — a still image that drifts, dots that turn into a walking person, a spin that refuses to go round
• Geometry — the Café Wall, a spiral that turns out to be circles, two lines your ruler disagrees with
• Depth — impossible objects, ambiguous corners, and a room that is the wrong shape on purpose
• Contrast — Adelson's checker shadow, and grays that will not match no matter how long you stare
• Color — afterimages, a gray picture you will see in full color, and a black-and-white disc that spins up colors
• Form — edges, surfaces and whole objects that were never drawn
• Attention — five demonstrations of what you are not seeing right now

Motion and flashing

Some illusions are in motion, and a few have a flashing/strobing effect. These are protected with a warning that names what the effect is before anything plays.

Private by construction

No accounts. No analytics, no tracking, no third-party SDKs. The app collects nothing.