An apparition

Stare at the blue dots while you count slowly to 30.

Now close your eyes and tilt your head back. A circle of light will slowly appear. Focus on it, and look into it.

What do you see?

Try this again, but look at a white wall after 30 seconds. Do you still see it?

For a description of the image place your cursor over it (certain browsers only), or click here for an audio transcript.