The illusion was created by American scientist Adelbert Ames, Jr., a researcher at the Dartmouth Eye Institute and creator of a number of mind-bending visual tricks like this. This window is his most mind-warping illusion, and it’s easy to see why. Despite how it appears to the eye, the frame is always physically rotating in one direction — it’s just the mind that gets confused by its shape. Now, feel free to go ahead and get another cup of coffee after watching this a few times. Or several more cups of coffee after watching these, too.