Optical Illusion

After Image

Stare at the red dot.
What do you see when the image disappears?

See Another Random Optical Illusion

Scroll down for the answer and explanation.

Most people can see that the US flag appears when the image disappears and the screen is white in this optical illusion.

Explanation

The eye responds to an amazingly wide variety of light sources, from moon light to direct sunlight. It tries to adjust for the present light level and color of light. After you have been staring for a while and the light source disappears, you will see the complimentary color appear, due to a fatigue of the retinal process. Here, the complimentary colors appear as an image of the US flag in this optical illusion.