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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.

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The collection

Original plan-view diagram of Pepper’s Ghost: a hidden figure is reflected in angled glass, appearing as a virtual figure on the visible stage.

Pepper’s Ghost

Henry Dircks and John Henry Pepper

A figure appears on an empty stage, transparent enough for the scenery to show through. Its real source is hidden elsewhere.

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Bertrand’s 1865 engraving showing a Pepper’s Ghost stage, audience sight lines and the concealed illuminated figure beneath it.

Victorian ghost shows — Pepper at the Polytechnic

John Henry Pepper; optical arrangement developed with Henry Dircks

A ghost shares the stage with a living actor, then fades away. Victorian ghost shows turned hidden performers and sheets of glass into public spectacles of apparent presence.

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Original comparison of rainbow-hologram viewing: two side-by-side views of a generic sphere show horizontal parallax, while vertically stacked views change from red to green to blue without adding a new vertical perspective.

Rainbow holography — Benton’s Sphere

Stephen A. Benton · Sphere, made at Polaroid

A hologram becomes visible in ordinary white light. Move sideways to explore depth; move vertically and its colour changes through the spectrum.

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Apollonian Gasket — Tangent circles fill gaps with smaller and smaller circles.

Apollonian Gasket

Classical circle geometry; later mathematical development

Tangent circles fill gaps with smaller and smaller circles.

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A black-and-white drawing of a woman at a dressing table; her reflection and the surrounding objects also form a skull.

All Is Vanity

Charles Allan Gilbert (1873 – 1929), American illustrator

You should experience a 'Gestalt switch' - a change - as your experience flips between being of a woman and being of a skull.

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A grey pattern of rectangular panels with vertical striped gaps that conceal circular forms in the Coffer illusion.

Coffer Illusion

Anthony Norcia, vision scientist at the Smith-Kettlewell Eye Research Institute in San Francisco.

You should experience a 'Gestalt switch' between seeing the image as a containing a pattern of squares versus a pattern of circles.

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Reutersvärd’s triangle — A triangle of blocks recalls Reutersvärd’s pioneering impossible figure.

Reutersvärd’s triangle

Oscar Reutersvärd; modern drawing by László Németh

A triangle of blocks recalls Reutersvärd’s pioneering impossible figure.

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Escher’s Belvedere: people occupy a pavilion whose columns connect incompatible upper and lower levels.

Belvedere

Maurits Cornelis Escher (1898 - 1972), Dutch graphic artist.

You should experience a sense of perceptual confusion as you note the paradoxical nature of the building and other features in the lithographic print.

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Three cylindrical prongs apparently connected to two rectangular supports.

Impossible trident

Original creator uncertain; reported by D. H. Schuster

Three prongs quietly become two supports.

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After the Hunt — Hunting equipment and game appear to hang against a real door.

After the Hunt

William Michael Harnett

Hunting equipment and game appear to hang against a real door.

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Boilly’s painted tabletop with playing cards, letters, coins, music, and tools.

Trompe-l’œil Tabletop

Louis-Léopold Boilly

A painted table surface seems covered with cards, papers, coins, and tools.

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Enlarged image from the selected gallery entry