Illusions of light while falling asleep - How common? And why?

Ever since I was a kid, I have often seen an illusion of moving lights as I was falling asleep. Not every night, but more often than not. When I was small, it seemed like I was seeing hoops of light moving from behind me, into my field of vision, and then out into nothingness, usually taking just a second or two. The hoops were distinct and fairly bright. Now they have faded and are as likely to be bars as hoops, but the illusion is still there.

Since they haven’t killed me yet, I’m not worried that they may be dangerous :wink: In fact, they are rather soothing, and if the fading means that they’ll disappear someday, well, I’ll miss them when they’re gone! But when I have mentioned them to friends, the answer has always been essentially: “Huh. That’s weird.”

So I’m asking:
Is there a name for this sort of thing - illusions of moving lights or similar while falling asleep?
How common is it?
Is it known what causes it, or is it just one of those weird things?

An ophthomologist once told me that flashes of light in my vision were a sign of retinal detachment. But that is supposed to be happening while I’m fully awake.

You’ve reminded me, though, that when I was little I would often have, I dunno, “visions?” of purple and green shapes kaliedescoping behind my eyelids just before I would fall asleep. Haven’t had one of those sessions in years.

I get a purple blob that starts out large, and then appears to spiral down a drain. Always have; only in darkness and a restive state.

A few years ago, it occured to me that maybe it has something to do with blood flow behind my eyes, because it’s in synch with my pulse.

The illusions of light are “phosphenes”, sensations during falling asleep are “hypnagogia”. Sorry can’t elaborate right now, at least here’s some terms to search for. Yes, it’s pretty common, we just seem to be wired that way.

When I’m falling asleep and I hear a sharp noise (a “pop” or “click” from the old building or the television set cooling down) it is accompanied by a bright flash in my closed eyes. The funny thing is, I seem to see the flash a fraction of a second before I hear the sound.

When I was little, I used to “see” images of traveling down a tube or a tunnel, not unlike the Doctor Who opening (which I hadn’t seen at the time), but not anymore. I also used to scrunch my eyes into the crook of my arm to enjoy the “light show” it produced.

Light travels faster than sound, y’know?

I have something similar that’s incredibly obnoxious: occasionally, when I’m lying in bed in a dark room with my eyes closed, I’ll get the sensation of looking into an uncomfortably bright light. That one gets old pretty quickly.

I was just thinking last night (as the lights were flashing behind my eyes while I was trying to go to sleep) that I should start a thread… The Dope does that to me all the time. Am I the only one?

In anycase, I have often been awakened by the flashy lights, only to open my eyes and find my room to actually be darker than what was behind my eyelids. It’s really annoying because there’s no way to turn it off…

Something else. When I wake up in the night, I can sometimes still see images from my dream in the darkened room when my eyes are wide open. It seems to take several seconds for these hallucinations to disappear.

I get exactly that - in my case I see something like the picture in the Wiki piece on Phosphenes only symetrical, a bit like a spider’s web drawn by Aubrey Beardsley

I have very weak Synesthesia (usually it’s just associating colours with words, eg each day of the week has a different colour) and I presume it’s connected to that – the senses getting more crossed-over as sleep approaches

I get those! Always deep yellow, and an obscene purple- ish that is almost black but somehow luminescent. I like to think it’s octarine.

When I close my eyes, I see a pale blue donut floating on a background of black. Sometimes the edges of the donut are brighter, like the “silver lining” of a cloud.

When I close my eyes, I get undulating checkerboard patterns, usually in green/yellow, orange/yellow, green/purple or orange/purple. I’ve always found checkerboard patterns to be reassuring, because that’s what the dark behind my eyes looks like.

Wait, holy shit! I just clicked the phosphene link and that’s exactly what it is, only in technicolor rather than black and white. Except that I don’t have to rub my eyes or put pressure on them to see it, I just close them and it’s there.

I have learned something new today. And it makes me happy.

I, too sometimes get a flash of pattern if there’s a sharp sound when I’m drifting off. It’s not nearly as complex as the phosphene picture in C B P’s post, more like a lattice or an array of spots of yellowish-white against a ‘dark’ background. It’s just an instant, not lingering at all. I’d been meaning to write a post asking if this was a common phenomenon but now I don’t have too.

Wait long enough and the Dope answers everything.

I often get a sudden flash of light, like a light went on outside my window. I open my eyes and there is nothing different. It’s never in a pattern or anything.

Also, when I was young, I’d rub my eyes hard to get the weird pattern of lights! It kinda hurt a bit after though.

I have something like this as well that has been bothering me for a looong time. Every time i close my eyes i see a pattern on the back of my eyelids, but i cant for the life of me make it out! it’s very frustrating–I have pretty bad eyesight, and this feels like my eyesight got a thousand times worse and i’m looking at some grand pattern of the universe but just can’t make it out. and the more I try to focus the more the patterns elude me. I actually want to get contacts just to see if I can make the patterns out any better with them on.

Another strange thing I have with my eyes is that I can make out an annoying transparent thing in my field of vision, but just out of my focus point. When I was younger I thought that it was some kind of single celled organism living on my cornea, because thats exactly what it looks like–it looks like a little group of cells as you would see them through a microscope, except they’re on my eye. If I move my eyeball the thing moves too, but because its not dead center on my eye, it moves away when I try to look at it. usually results in me flicking my eyeballs back and forth all jittery like stephen hawking watching a sped up tennis match.
It just struck me that it might be a tiny scratch on the surface of the eyeball, and light diffraction makes it look like little micro bacteria.

Those are called ‘floaters’. They are cells in the liquid inside your eyeball.

Me too. The pattern I see is a checkerboard of alternating light and dark with the squares at a 45 degree angle.