Close your
eyes.
Gently,
rub the
lids with your
hands. You will initially see
blackness, but if you continue, you will begin to see
shapes emerge from the
rippling nothing before you.
Abstract and
impossible geometric figures will
parade from one eye to the next, and you may experience some
visions akin to a
video feedback loop.
Eventually it passes, to be replaced by a dull glow, and your lids hurt a bit where the eyelashes chafed against them.