If you have at least one friend who loves to spook their group chat with trippy images, you know the exact brand of person who thrives on unsettling optical illusions. Much as I hate to admit it, I’m the kind of skeptic who still ends up staring—and then staring again—any time one of these brain-bending photos crosses my feed. The latest culprit: a picture that resurfaced on X (formerly Twitter) after podcast host Joe Rogan gave it a signal boost, instantly racking up millions of new eyeballs and no small share of shivers.

Originally posted in August of last year by user Josie Glabach, the snapshot has been viewed well over 22 million times. In her caption, Glabach offered a piece of advice aimed at people like me: “Nearsighted folks, remove your glasses and move your phone away from your eyes. Focus on the blonde girl.” A simple set of instructions—yet it’s the key to understanding why this image is simultaneously clever, creepy, and fascinating.

Before we dive in, a quick refresher: nearsightedness (also known as myopia or shortsightedness) is a very common vision condition in which nearby objects look sharp while distant ones appear fuzzy. The Mayo Clinic sums it up nicely—think of it as viewing the world through a camera that’s forever set to macro mode. As someone whose prescription lenses are basically small magnifying glasses, I can confirm that the “blur trick” used in this optical illusion feels eerily familiar.

So, what exactly does the photo show? At first glance, nothing more than two little girls—one blonde, one brunette—sitting together on what appears to be a garden wall or perhaps a park bench. Some leafy greenery frames the scene, and the lighting is soft enough to make the moment look almost pastoral. Scroll past too quickly and you’ll see nothing but a sweet, boring snapshot destined for the family album. But slow down and follow Glabach’s directions, and the scenery morphs into something that would make M. Night Shyamalan proud.

Here’s how it works. If you’re nearsighted, take off your glasses or squint a bit so the details blur. If your vision is crystal-clear, lean closer to your screen until the image pixelates ever so slightly. As the sharp edges fade, darker shapes within the photo start to rearrange themselves in your peripheral vision, coaxing your brain to swap one reality for another. Suddenly, the blonde child’s wispy hairline and shadowed neck combine to form the sockets of a pair of eyes. A darker patch created by the folds in her sweater becomes a subtle nose, and a faint crease in the fabric below outlines a mouth. Together, these elements conspire to reveal the unmistakable face of an adult woman staring back at you—one you absolutely didn’t notice a second ago.

Creepy? You bet. But it’s also a textbook example of pareidolia, the psychological phenomenon in which the human brain “sees” familiar patterns—especially faces—where none actually exist. We evolved to recognize faces quickly for social survival, so our neural circuitry jumps at any chance to fill in the blanks. The optical illusion’s power hinges on that reflex. Highlights in the blonde girl’s hair mimic cheekbones, shadows in the greenery resemble contour lines, and the sweaters’ folds provide just enough contrast to trick our visual cortex. Once the illusion registers, it’s hard to “unsee” it, even when you put your glasses back on or step away from the screen.

If you have 20/20 vision and felt cheated because the hidden face didn’t pop instantly, here’s why: clarity makes your brain cling to literal detail. Only when the edges soften does the mind loosen its grip and allow the gestalt effect—seeing the whole instead of the parts—to take over. That’s why nearsighted folks often experience these illusions more readily; the blur from uncorrected vision provides a built-in, real-world filter that photographers try to replicate with depth-of-field effects.

Beyond the wow-factor, images like this remind us how easily perception can be manipulated by context, lighting, and focus. They also prompt a bigger conversation about how reality is, to some extent, a negotiation between our senses and our brain’s need to organize chaos. Whether the illusion leaves you amazed or uneasy probably depends on how comfortable you are with the idea that your eyes can’t always be trusted.

It’s worth noting that not all optical illusions rely on blur. Some use perfectly crisp geometry, color contrast, or impossible perspectives—think of Escher’s staircases or the infamous dress that divided the internet into “blue-black” and “white-gold” camps. The common thread is that every trick exploits a gap between what our eyes gather and how our brains interpret it. This particular photo weaponizes depth-of-field haze, turning an ordinary scene of children at play into a hidden portrait of a woman who isn’t really there.

So, the next time a “look twice” picture pops up on your timeline, don’t be too quick to scroll on. Instead, take a moment to examine the shapes, shadows, and negative spaces. Ask yourself what else those lines could represent. You might uncover a hidden image—or you might simply become more aware of how malleable human perception truly is. Either way, optical illusions offer a fascinating peek into the way our visual system edits life on the fly.

In the end, whether you’re a fan of mind games or someone who’d rather avoid that late-night jolt of uncanny recognition, one truth remains: the picture you see at first glance isn’t always the whole story. And that single realization can be more eye-opening than any illusion.