Interesting fact:

Well? Did you see it? Though it can hurt to bring this illusion to life, it’s fascinating how it works. P-cells in your eyes help you to see things in high detail, though they’re not great with movement or in low contrast environments. M-cells, on the other hand, help you see fast moving objects and work well with low contrast. By sitting still and looking at your phone or computer, you’re using your P-cells. However, once you start moving, you rely on your M-cells. Suddenly everything becomes clear as the gaps are filled in! The weird thing is, if you just stare at the image without moving at all, you’ll gradually see less and less of it. Weird, right?