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 the same photo, flashed back and forth with a large object added, removed, or recolored between them, and most viewers stare right through the difference without noticing.

Cognitive

Inattentional Blindness (The Invisible Gorilla Experiment)

Ask viewers to count basketball passes in a short video and roughly half never notice a person in a gorilla suit walking through the middle of the scene.

Cognitive

Thatcher Effect (Upside-Down Face Illusion)

Flip a photo of a face upside down after crudely inverting the eyes and mouth, and the distortion becomes almost invisible - proof that upright face recognition runs on rules that flip off along with the picture.