The Persistence of Vision

These images were all created by a series of programs which I wrote in Visual Basic. See the bottom of this page for instructions about downloading a shareware copy of a video demo.

Algorithms for Afterimages

The "persistence of vision" is the neurological phenomenon in which the eye or the brain continues to see an image after the stimulus for it has been removed. All of us see afterimages, the most notorious being the spot left after a flashbulb of a camera goes off.

If you observe closely, you will notice a progression of color changes as an afterimage fades. This is because the sending units of the retina -- the receptors for red, blue, and green -- recover from their stimulation at differing rates. Blue recovers first, and then green, and red is the last to be ready to "fire" again.

The temporarily de-activated receptors cause a perception of an image. It is neither "off" (no stimulus) nor "on" (stimulated), but "not usable". The brain translates this condition into an image which is not as bright as full stimulation, but not dark, either.

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Download a Persistence of Vision Demo Video

You may download a demo video showing a moving version of some of the above images. The program and data files are archived in a 282KB file called PERSIST.ZIP. Unzip them into a folder of their own and run "Player.exe". The unzipped files will take up about 2MB.

I do not own a Developer's Toolkit for VB, so the program will require that the DLL files for running VB 3.0 or 4.0 already exist on your system. If it refuses to run, this is probably why.

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The Persistence of Vision

Last Updated September 19, 1997
Web Page by Ned May (nedmay@moonstar.com)
URL http://luna.moonstar.com/~/nedmay/chromat/persist.htm
All images and text are ©1997 by Edward S. May unless otherwise noted. All rights reserved.