Rings around all twelve dots.
Lighter or darker?
Twelve vanishing dots
There are twelve black dots. Can you see all twelve at once?
Hardly anyone can: you only see the few near where you are looking, and the others blink in and out.
Why? Away from the middle of your eye you see less sharply, and there the small dots get lost among the gray lines: your brain fills the gaps in with more grid. Jacques Ninio and Kent Stevens found it in 2000; this is our drawing.
Picture: Drawn by Science Playground