thrumirror.com A different way of seeing

Optical illusions & the art of seeing

Explore optical illusions, impossible objects and illusion art with pictures, viewing instructions and explanations. Follow the science and history behind each example, from classic visual puzzles to fractals and camouflage in nature and human design.

Ranked by everyone’s votes. Thumbs up adds 1; thumbs down subtracts 1. Select your vote again to remove it.

The collection

Parallel long lines crossed by groups of short oblique hatch marks.

Zöllner illusion

Johann Karl Friedrich Zöllner

Short crossbars make parallel lines seem to diverge.

Score 0
A photograph of strawberries on a plate under a cyan tint, used to demonstrate colour constancy.

Grey strawberries

Akiyoshi Kitaoka, Professor of Psychology at Ritsumeikan University

You should have the experience of red strawberries in the picture, but the picture doesn't contain any red colour.

Score 0
Four black-and-white striped squares with alternating horizontal and vertical orientations, used in the McCollough effect.

McCollough Effect

Celeste McCollough (1927 - 2023), American psychologist

The black and white test figure will have taken on an illusory tinge of colour - the horizontal white stripes appear tinged red, while the vertical stripes appear green.

Score 0
Moiré Pattern — Overlapping fine patterns produce a larger rippling pattern.

Moiré Pattern

Pattern interference; drawing by Fibonacci

Overlapping fine patterns produce a larger rippling pattern.

Score 0
Impossible wooden cube — A real wooden construction looks like an impossible cube from one view.

Impossible wooden cube

Wmccallie

A real wooden construction looks like an impossible cube from one view.

Score 0
The Ambassadors — A double portrait with a skull that emerges from an oblique view.

The Ambassadors

Hans Holbein the Younger

A double portrait with a skull that emerges from an oblique view.

Score 0
An animated black-and-white spiral used to induce a motion aftereffect.Moving image

Waterfall Illusion

Robert Addams popularised the illusion in 19th century; but it was known much before.

You should experience the dots in the test pattern as moving - even though they are stationary.

Score 0
Andrus’s nuts and bolts — An arrangement of real nuts and bolts looks impossible from its chosen view.

Andrus’s nuts and bolts

Jerry Andrus; photograph by Sgerbic

An arrangement of real nuts and bolts looks impossible from its chosen view.

Score 0
Old Time Letter Rack — Old papers and everyday objects seem attached to a real rack.

Old Time Letter Rack

John Frederick Peto

Old papers and everyday objects seem attached to a real rack.

Score 0
Impossible Valknut — Three interwoven triangles hide several impossible connections.

Impossible Valknut

AnonMoos

Three interwoven triangles hide several impossible connections.

Score 0
A white dove and an outlined cloud against a red field, used in a colour-adaptation demonstration.

The Colour Dove Illusion

Yuval Barkan and Hedva Spitzer

In the first few seconds you should notice that the dove appears red—a faint version of the red that was in the background of the first image. You are experiencing a positive afterimage…

Score 0
Enlarged image from the selected gallery entry