Optical Illusion Skull Art - Collect images like these for a fun little hobby. Like this one, Skulls, by artist Octavio Ocampo. Look closely and you'll see a bakery worker, but squint your eyes and you'll see a skull.
If you stare at the crosshair long enough, you will see a green dot moving around the purple dots. If you keep staring, eventually the purple dots disappear and all you see is the nonexistent green dot.