More precisely, the human brain can develop a negative! Now this is just freaky and it works:

Instructions:

1. Stare at the red dot on the girl’s nose for 30 seconds.
2. Turn your eyes to a plain surface (your ceiling or blank wall).
3. Blink repeatedly and quickly while still looking at the plain surface.
4. The brain makes the negative into a positive.

Now just imagine what goes on in the brain when just looking at an image…