Richard Gregory and the Café Wall Illusion

Everybody loves a good origin story. Most people prefer the stories of superheroes and villains, but here at the Museum of Illusions New York City, our favorite origin stories all revolve around optical illusions. They might not be as riveting or dramatic as your favorite Marvel prequel, but they are fascinating. Today, we would like to tell you a really interesting origin story- the story of Richard Gregory and the Café Wall Illusion. 

A little bit trippy, a little bit funny, and very influential in the world of optical illusions. We, and our guests, love the Café Wall. So, without further ado, let’s talk about how one man’s discovery influenced the world of optical illusions.

Richard Gregory’s Café Wall Illusion

The Café Wall Illusion as we know it was first noted by psychologists Richard Gregory and Priscilla Heard in 1973. Gregory actually credited the discovery of the illusion to one of his colleagues, Steve Simpson, who noticed something peculiar about the outside wall of a café in Bristol. Though a dark and light tile pattern is rather common for both residential and commercial spaces, this particular tiled wall felt… off. Take a look at the image below and see for yourself.

Richard Gregory standing in front of the cafe wall illusion that he discovered in 1973. Used for the Museum of Illusions NYC blog.
Richard Gregory standing in front of the original café wall in Bristol.
image: Creative Commons Attribution-Share Alike 3.0

As you can see, the dark green and white tiles are placed in an odd way. Their skewed placement caused the parallel grout lines to appear curved. Richard Gregory and his colleagues noticed this and set out to study exactly what causes our brains to perceive the wall this way.

Other Discoveries of the Café Wall

Believe it or not, Richard Gregory’s Café Wall Illusion was a rediscovery. Gregory popularized the illusion, but it was actually first discovered in 1898 and dubbed the “Kindergarten Illusion.” Though information on the Kindergarten Illusion is limited, we do know that it was first published in a psychological journal penned by A.H. Pierce. This early rendition of the Café Wall was one of many illusions based on a “shifted checkerboard.”

In the decades since Gregory rediscovered the illusion in 1973, a new version of the Café Wall takes the internet by storm every few years. This alternate Café Wall, created by Victoria Skye, is one of many that has had the internet buzzing recently.

How the Illusion Works

Like many of the optical illusions that we know and love, the effect of this illusion is still up for debate. What we do know is that the high-contrast colors and slightly “off” pattern causes our retina to send an incorrect image to the brain. It might not be a perfect end to the Café Wall Illusion’s origin story, but at least it leaves some room for a sequel. 

The Cafe Wall Illusion used for the Museum of Illusions NYC blog
The Café Wall Illusion

What we find even more interesting than the scientific explanation behind the Café Wall Illusion, is what it says about the flaws of human perception. When looking at the Café Wall Illusion, or any tiled surface, we intuitively know that the grout lines should be parallel to one another. Even though we know that the lines should be straight, we still perceive them as curved. Part of the allure of optical illusions is that they are concrete evidence that everything is not always as it seems.

See the Café Wall Illusion in Person

Speaking of “not always as it seems,” do you want to challenge your perception of the world in person? If so, then it’s time to plan a visit to the Museum of Illusions NYC. Here, you can see the Café Wall Illusion and many others up close and personal. Click here to book your visit, and get ready to question the way you see the world.