Persistence of Vision Test

Persistence of Vision Test is a screamer game. The viewer is prompted via audio instructions to stare into a small black dot within a white background. During this time, phrases such as "Continue concentrating on the dot" appear. Two black lines appear above and below the dot, respectively, and the viewer is instructed to concentrate on these as well. However within 30 seconds a picture of a human skull appears and covers the dot along with a scream.

This link contains a screamer:

web.archive.org/web/20051027014520/vision.badgerville.org/