About Through Mirror
and the collection.

A collection, still growing

The archive currently contains 179 entries, including images and linked demonstrations. It brings together geometric illusions, ambiguous figures, impossible objects, contrast effects, color effects, motion illusions, illusory contours, classical illusion paintings, fractal patterns, and animal camouflage.

There is no definitive list of “all famous illusions.” This collection is a researched starting point, rather than a claim of completeness. Fractals extend the archive into mathematical patterns; they are not necessarily optical illusions. Categories describe the viewing experience; some illusions fit several.

Architecture that changes what you see

The Architecture section follows eleven examples of painted space, forced perspective and reflection, beginning with Gozo Cathedral’s false dome. Each links to historical or project sources and explains the role of viewpoint. Locally stored photographs have individual credits; modern installation photography without established reuse terms remains linked to its source.

Animals hidden in plain sight

The Animals section explores seven examples of optical camouflage: background matching, countershading, leaf-like shapes, hidden outlines, changing skin patterns and partial transparency. These are biological adaptations whose effectiveness depends on the surroundings and the observer. Each entry includes viewing prompts, scientific sources and individually credited photographs.

Geometry beyond intuition

The Strange objects section explores five mathematically consistent shapes, including the Möbius strip, K-dron, and Klein bottle. Original explanatory diagrams accompany practical experiments and linked sources. Each entry distinguishes objects we can build in three dimensions from surfaces and solids that need an extra dimension for a faithful representation.

Names are not always origins

A famous name can hide an earlier publication, an independent discovery, or a later redraw. Each entry distinguishes historical attribution from the creator of the image shown here. Uncertain dates and disputed credits are marked rather than presented as settled facts.

Sources you can follow

Entry pages link to research, original publications where accessible, museum collections, and specialist explanations. Michael Bach’s visual perception archive is a useful research guide; historical claims are checked against additional sources where possible.

Explanations describe the effect and relevant mechanisms. They do not imply that every illusion has a single, conclusively established explanation.

The Illusions Index

All 66 articles from The Illusions Index are included, with full text, instructions, effects, references, and author citations. Existing subjects share one catalog entry. Imported text is licensed under CC BY-NC-SA 4.0; paragraph formatting is adapted for this archive. Each article credits its authors and F. Macpherson as editor.

Media licenses are separate from article text. Explicitly permitted images are stored unchanged; other images, interactive demonstrations, audio, and video remain linked to their sources. License labels and media credits are retained as supplied, including unspecified versions.

Images with their own stories

The M. C. Escher collection guides you through twelve famous prints with museum links. Original Escher prints require reproduction permission and are not included in the downloadable image archive. His locally stored portrait is credited on that collection page.

The original illustrated collection uses Wikimedia Commons images with reusable licenses or public domain status. Each detail page names the image creator, links to the file page and license, and offers a locally stored download. Most files are unchanged originals; selected large artworks use Commons size renditions, clearly identified on their detail pages. Later redrawings illustrate the phenomenon and are not passed off as historical originals.

Animated images wait for you to press Play. Their gallery previews are still frames. Large static images have separate resized WebP previews.