Peanuts
by pragma_x (644215)

A little slash-trivia here:

You can also notice the refresh of a CRT if you chew on something hard, like peanuts, while staring at the screen. The crushing action of your teeth vibrates your head just enough to interface with the screen's refresh rate, causing the picture to "bounce" and shear in your field of view.

Re:Peanuts
by Hythlodaeus (411441)

The same can be achieved by humming the second F below middle C.

Re:Peanuts
by Rogerborg (306625)

DON'T DO IT; that's the Brown Note [wikipedia.org].