The Best Optical Illusion of the Year Will Mess With Your Head

How a game developer used his love of programming to create the trippiest illusion of 2019.
Image: Frank Force

Everyone likes a good optical illusion. The right kind of trick can instill a sense of wonder in even the most jaded viewer.

Every year, the Neural Correlate Society, a nonprofit that promotes scientific research into perception and cognition, runs a contest to find the world’s best illusion. This year’s winner is a Dual Axis, a series of twisting rings that appear to move clockwise, counterclockwise, and up or down, depending on how you’re looking at it.


The Dual Axis illusion is the work of Frank Force, an Austin-based game developer. “I've worked on DOOM, Red Faction: Guerrilla, Psi-Ops, and Starhawk,” he told Motherboard in an email. “A little over a year ago I decided to quit my job to focus more on the creative side of things and learn some new skills."

Programming the Dual Axis took Force a day of coding in JavaScript. “The programming went quick but figuring out how to best present things took a few iterations,” he said. Force has uploaded the code behind the illusion to GitHub so others can see the work it took to make the impressive visual trick.

This isn’t Force's first illusion, just one of the best in a long series of visual pieces he’s created while practicing JavaScript. “Recently I have been doing a deep dive into tiny coding with JavaScript. It's a type of art where you write small programs that do interesting stuff,” he said. “Think of it as a programming haiku.”

In 2019, Force uploaded more than 600 coding haikus to Dwitter, a website that collects JavaScript pieces. Every upload can only use 140 characters. “I experimented with a huge variety of stuff from art to music and even some playable games,” Force said. “In fact, I have made so much that I had to build a special database to browse through all my dweets.”

While fiddling with equations one day for his JavaScript projects, Force started playing with Lissajous curves—a system of equations which create complex harmonic action as seen in Force’s illusion. “I noticed that if I focused, I could seem to make it rotate around either axis,” Force said. “These are well known mathematical shapes, but I was unable to find a mention of this illusion so I dug into it a bit more and after testing it on some people it seemed like a hit.”

The Dual Axis is hypnotic and beautiful. “The ‘when you see it’ moment is extremely satisfying for this one,” Force said. “Also it is kind of a metaphor for seeing things from multiple points of view, which is more important now than ever.”