Editorial & Sourcing Policy

This page explains how Optical Wonderful's content gets made - how illusions are researched, how historical attributions are checked, how images and illustrations are sourced, and what happens when something turns out to be wrong.

Research and fact-checking

Every illusion page covers three things: what the effect looks like, the current scientific understanding of why it happens, and - where it exists - the documented history of who discovered, formalized, or popularized it. For the "why it happens" explanation, we lean on the established consensus in vision science and cognitive psychology rather than novel or fringe theories, and where the science genuinely isn't settled (the moon illusion is a good example - several competing explanations remain under active discussion), we say so explicitly rather than presenting one theory as the final word.

For historical attribution, we try to distinguish between who is popularly credited with an illusion and who can be more precisely documented as its first publisher or formal describer - these aren't always the same person, and conflating them is one of the more common errors in illusion writing elsewhere online. Where a date, name, or detail can't be pinned down with confidence, pages say so with appropriate hedging ("widely credited with," "generally dated to") rather than stating an invented precise fact.

Image and illustration sourcing

Classic illusion diagrams are more encumbered by copyright than people often assume - many of the canonical images associated with famous illusions were created or published by specific researchers, artists, or publishers who retain rights to them, and reusing them without a license is not automatically fair use just because the underlying illusion is old or well known. Rather than take that risk (or use vague, uncredited "found online" images), illustrations and interactive demos on this site are built from scratch as original CSS, SVG, and small JavaScript, matched as closely as possible to the actual visual structure of each illusion. See the Image Sourcing Guide for more on this approach and its tradeoffs. Where an illusion depends on real photography or footage that can't be feasibly recreated as original artwork (for example, illusions tied to a specific famous photograph), the page explains the effect in detail and links to further reading rather than reproducing a copyrighted image without a license.

Corrections

If you spot a factual error - a wrong date, an incorrect attribution, an outdated scientific explanation, or a broken link - please use the Contact page to let us know, ideally with a source if you have one. Corrections are reviewed and, where verified, applied directly to the page; for anything beyond a minor factual fix, the page's "last updated" date is refreshed so the correction is visible.

What this site is not

Optical Wonderful is not a peer-reviewed publication and doesn't claim to be one. It's a reference and explainer site written for a general audience, built on publicly available scientific literature and well-documented history. For primary research, the Science of Perception pages and individual illusion entries point toward the kind of source (researcher names, study concepts, foundational papers) worth searching for directly if you want to go deeper than a general-audience explanation.