It’s All in Your Head: 17 Optical Illusions Prove You Can’t Trust Your Brain

These Squares Are Perfectly Straight

In these two illusions from Kitaoka, the squares are perfectly straight. It’s the placement of the smaller squares within them that make them appear to lean or bulge.

Cycloid Optical Illusion


Do you see a circle of eight dots rotating as it spins within a larger circle in this video? Well, keep watching. Each individual white dot is actually moving in a straight line, but they aren’t moving at a constant speed. It all has to do with ‘cycloid motion,’ which is the motion of a point on a circle as it rolls. Astronomer Phil Plait explains how it works at Slate, noting “When a circle rolls along a straight line, if you watch a single point on it you can break up the motion into two dimensions: Horizontal and vertical motion. These motions aren’t constant, but depend on the sine and cosine of the time elapsed. They start off motionless, accelerate to a maximum speed in the middle, then slow back down to zero… and in each direction, the point moves linearly! It’s only when you combine them that you get the cycloid.”

These Lines Are Perfectly Parallel

These lines are all perfectly parallel to each other -so why do our brains insist they’re zig-zagging? A variant of the ‘Cafe Wall Optical Illusion,’ this image was created by Atlanta magician Victoria Skye. The alternating colors and series of small shapes and patterns within the image all come together to trick our perception.

Rotating Crosses Seem to Change the Background Color

What’s the foreground of this image, and what’s the background? Is the background color changing as the crosses rotate? What’s actually happening here is that the white crosses rotate one way and then the black crosses rotate the other way. Focus on one diagonal line of crosses at a time to see how it works.

Anamorphic Illusions: The Objects On This Table Aren’t What They Seem

This one is extra fun because it deals in physical objects within three-dimensional space rather than just a graphic. Youtube channel Brusspup, known for its incredible illusions, created what looks like a boring dresser covered in everyday objects – a photograph of a cat in a frame, a rubik’s cube, a camera, a ball cap. But watch the video to see what’s really happening.