When I lie in bed at night, in total darkness, and close my eyes, I see thousands of coloured dots that swarm together and form (in my case) nighmarish pareidoliac faces, chimeras and objects.

What is the term for this phenomenon?

It is distinct from but loosely related to muscae volitantes—the floating threads and particles in the vitreous humor (also called "eye floaters"; the perception of which is known as myodesopsia). The word phosphenes comes tantilizingly close, but this describes "an aphotopic ring or spot of light produced by pressure on the eyeball" (italics mine). Pressing against one's closed lids intensifies the photisms I am trying to describe (a witch's face is fulminated in stroboscopic lightning), but is not required to produce them (the witch's face was there to begin with).

Any suggestions?

Perhaps it's phosphenes anyways, because of ambient air pressure and such?

You know, I think you're right. Maybe it's the eyelids that put pressure on the eyeballs, producing phosphenes (or "gray figures walking between behives, or small black parrots gradually vanishing among mountain snows, or a mauve remoteness melting beyond moving masts", as Nabokov describes his in Speak, Memory).

Hydra: I wish I could see stuff like that

Interesting but potentially unrelated--the same phenomenon is more common in people who suffer from migraines.

And synesthetes.

At night, in the dark, apply gentle pressure to your closed eyelids with your fingers—holding them very still. Slowly increase and decrease pressure, and you will probably see strange stuff (green and blue lightning, wheeling geometric spirals, polyhedra skeletons flashing pink, and so on).

Also prisoner's cinema... See: http://en.wikipedia.org/wiki/Prisoner%27s_cinema

After surgery for a detached retina, I was told by my doctor that the retina and interior of the eye has no pain/tactile nerves and that odd light patterns and flashes I was experiencing at the time were indicators of pain/discomfort.

So it's phosphenes, after all.

What do you think, tswum? Is it worthless enough? (Honorable mention is all I ask).

Em--
phos·phene (fsfn)
n.
A sensation of light caused by excitation of the retina by mechanical or electrical means rather than by light, as when the eyeballs are pressed through closed lids.

The American Heritage® Stedman's Medical Dictionary, 2nd Edition Copyright © 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.


What about after-image?