About The Illusions Index

The Illusions Index is a fully searchable, interactive curated collection of illusions. The illusions are categorised into different types, allowing you to search for, and compare, illusions that fall under one or more type. Staff and students at the Centre for the Study of Perceptual Experience have researched each illusion to provide detailed information about what it teaches us about the philosophy and psychology of perception.

The Illusions Index is an open-access resource, intended for use both by the general public and by researchers in the philosophy and psychology of perception, and beyond. The pages for each illusion are stable URLs, so researchers can easily cite illusions in scholarly work by referring to those URLs. The Index is funded by the Centre for the Study of Perceptual Experience, the School of Humanities, and the College of Arts at the University of Glasgow, and by donations from you. All we ask is that you cite the articles in The Illusions Index using the author and citation information indicated beside each article, and conform to the Creative Commons license (CC BY-NC_SA 4.0).

The Illusions Index was conceived of by Professor Fiona Macpherson, and designed and developed together with Dr Keith Wilson and Mucky Puddle.

More about Perceptual Illusions

Our senses are remarkable. They have evolved to allow us to accurately perceive a huge variety of things: colours, shapes, sounds, textures, tastes, smells, heat, location, direction, to name but a few. And they allow us to do so in very different conditions, such as bright sunlight, at dusk, in the air, underwater, in heat, and in cold.

As a consequence of this tremendous power and flexibility, our senses occasionally let us down and we fail to perceive the world accurately. However, we usually have to work hard to find the stimuli and the conditions that mislead senses, as they are so well attuned to the world. Thus, illusions are relatively rare.

However, when we find them, illusions often give us great insight into how our senses work, and how they usually work so astonishingly well. Illusions also intrigue us. It is fascinating to observe our senses get things wrong, and to continue to do so even when we know the nature of the illusion. And it is intriguing to ponder what we aware of, when we seem to be aware of something that isn’t there in the world in front of us.

About the Centre for the Study of Perceptual Experience

The Centre for the Study of Perceptual Experience facilitates analytical philosophical and empirical research into the nature of perceptual experience. Our researchers often work in an interdisciplinary manner drawing on philosophy, psychology, neuroscience, psychiatry, and human-computer interaction.

For further information, see our website or follow UofGCSPE on Twitter or Facebook.