Illusion Category

Cognitive & Perceptual Illusions

Illusions rooted less in the eye than in attention and expectation - including how much of a scene the brain quietly discards without you noticing.

Cognitive

Change Blindness Illusion

Two versions of a photo, alternating with a brief blank, differ in one large object, and most people take ages to spot it. Time yourself, then remove the blank.

Cognitive

Inattentional Blindness (The Invisible Gorilla Experiment)

Half the people counting basketball passes miss a gorilla walking through the game. Try a short lab version of the test and see how other visitors did.

Cognitive

Thatcher Effect (Upside-Down Face Illusion)

A face with its eyes and mouth turned upside down looks grotesque, until you turn the whole picture over and the distortion almost vanishes.