Source: http://gizmodo.com/5879004/your-brain-will-melt-after-you-see-this-negative-image
Want to add more wrinkles to that ol' brain of yours? Stare at the colored dots on the girl's nose in the photo above for 30 seconds. Then look at a white surface (blank browser, mayhaps) and start blinking. You should see a non-negative image of the girl. WHAT. BRAIN. MELTING. WHAT. OHMYGOD. Yep, that jiggly stuff in your head just processed a negative image. Sweet. [PetaPixel]