Stare at the cross between the faces. Don't look at the faces. Give it 10 seconds and see what happens to them. Click to pause.
What: The Flashed Face Distortion is one of the creepier ones on the site, and honestly one of my favorites. As you focus on the cross in the middle, the faces on the left and right start to warp… jaws get huge, eyes go a little alien, foreheads stretch, and these are some of the most famous (and good looking) faces on the planet. The moment you look straight at one though, it’s totally normal again.
It was found completely by accident in 2011 by Sean Murphy, an undergrad at the University of Queensland (I was born in Queensland!), who was lining up face photos for a totally different experiment and noticed they started looking horrible as he flicked through them [1]. Which, if you ask me, is the best way to discover an illusion.
How To: Keep your eyes on the cross, that’s really all there is to it. It takes a good 5 to 10 seconds to build up for me, and then it hits hard. If you want to check the faces are actually fine, click to pause and have a look, they all are.
You can mess with the speed, though around 4 faces a second seems to be the sweet spot for me, too slow and it fades out, too fast and it all just blurs together. The oval mask and black & white make the faces more similar, so the only thing changing is the face itself, and for me that makes it even stronger. Single face mode is a lot weaker, which is a pretty big clue as to what’s going on.
A heads up, it does flash quite a bit, so maybe give this one a skip if flashing images bother you.
Explain it: Nobody’s 100% sure yet, but the leading idea is that your brain judges each face against the one that came right before it in the same spot, so if a wide jaw follows a narrow one, it looks really wide… it’s essentially a caricature generator running live in your head.
Your brain is always recalibrating what an “average” face looks like (called face adaptation), and flashing faces at it like this sends that into overdrive. The faces are all lined up on the eyes, so the differences between them really stand out, and your peripheral vision isn’t great at detail anyway, so it leans on the overall shape of the face, which is exactly the part being exaggerated.
I've researched these optical illusions in my spare time but am clearly not any kind of expert and my explainations are pretty smooth brained, if you find something mis-cited, earlier examples, or general mistakes please new let me know via toymaker@toms.toys, be kind!