The phantom flag
Stare at the dot in the center of the flag for the whole countdown, without moving your eyes. When the image turns white, keep staring at the dot.
The experiment starts as soon as the page has loaded (JavaScript is required).
What most people do: For almost everyone, the flag’s real colors appear for a few seconds.
What just happened (read it after the experiment)
The cells in your retina that pick up a color get tired when they are stimulated for a long time. When the image disappears, their “opposites” win out for a moment: cyan leaves red behind, yellow leaves blue, black leaves white.
This is the opponent-process theory of color, proposed by Ewald Hering in the 19th century: your vision codes colors in opposing pairs, red and green, blue and yellow, black and white.
For a few seconds, you see an image that nobody else can see.
More experiments
Sources
- Ewald Hering, Zur Lehre vom Lichtsinne, 1878.