Don't know whether its just me being mental but thought I have to try this !
A few weeks back I was eating a pack of square crisps looking at my PC screen from the kitchen.
Now every time I crunched a crisp I got the illusion of a screen flicker, looked exactly like when you see a computer screen on the news or programs on the TV. Has something to do with refresh rates that makes the monitor look like it is flickering when recorded on a TV camera.
Now I can assure you I wasn't recording with a camera or anything but the screen definately flickered in the way mentioned when I was eating this crunchy snack ! Distance was approximately 5 metres.
So to find out if I was seeing things or going mental and need a trip to the local opticians or phsyciatric ward with the men in white coats. Try doing the same thing with a packet of square crisps (cheese flavour is my recommendation) or something equally crunchy and see what the results are.
Finally, I have a 15" Hansol CRT set at 800x600 on the desktop with a refresh rate of 75 Hz and 32 bit colour. Be interesting to see some results from TFT's etc !