OK, I looked and couldn’t find anything in the archives, so here goes:
When I close my eyes sometimes I can “see” an image of a geometric pattern, almost like a snowflake. The effect is most noticeable when there is a strobelike flashing of light, such as when I’m riding in a car and sunlight is filtering through trees.
I’m not seeing “floaters,” although I have those too, but I understand what those are. Nor is this the same as pressing on one’s eyeballs and watching the “light show” that that can produce.
And, sadly, I’m not doing drugs when I see this.
Some possibly relevent information: I’m extremely near-sighted and have been since childhood; I have a history of glaucoma in my family; I have astigmatism; I played with a Spirograph when I was a kid.
Any ideas?
See here: Visual Disturbances.
Now go see a doctor. Getting medical advice on the internet probably isn’t that reliable.
Ah, phosphenes. These are normal. You can get all kinds of colorful light shows, geometric and non-geometric, with a little gentle pressure on the eyeball.
Phosphenes are Nature’s own proof that the human neural net is innately psychedelic. 
Also seeMigraine with Aura. Skip down and look at the illustrations of the migraine hallucinations. I have personal experiences with these about 4-6 times a year. Is this the kind of thing you’re seeing?
So what does it mean if someone were to see these but with no occurence of headaches? For the record, I can see these things, too, when I close my eyes, though I seem to see them best in total-darkness, not under strobe lights like JonScribe. They’re nowhere near as bright as the ones shown on the web pages, but they’re noticable if I look for them. I haven’t had a headache for years, either, except for ones connected to running a fever.
I had just assumed it was just “background noise” from signals running near the visual cortex.
Punoqllads, I’m not saying he has Migraine Aura, I’m asking if it’s similar to what he sees.
FWIW, you can get migraine aura without a migraine headache (I do). But it’s not just something you see with your eyes closed, it blocks your daylight vision as well.
It doesn’t seem similar to the migrane aura, and no, I haven’t ever had a problem with migranes, nor are the images related to any discomfort.
The images are static, symmetrical and centered in the field of vision, which would seem to distinguish them from the migrane auras as displayed in the sites offered (thanks squeeg, BTW) and they are not visible when my eyes are open.
And I’m not convinced they’re phosphenes.
I didn’t mention in the OP that I’ve seen these since childhood.
I’ve asked eye docs before, and have only gotten shrugs. Since they didn’t notice any other indication of serious problems, they haven’t been concerned. Nor am I. Just curious.
If I close my eyes tightly for long enough (say 10 -20 seconds) I get all the light show effects - an overlaying chess board pattern is quite common.
No idea why though.
I’m sure there was a Cecil column on flashing lights in the eye, which may or may not be related.
I know exactly what you’re talkijng about; I see very intricate symmetric snowflake/kaleidoscope patterns when I close my eyes (under certain conditions.
For the record, there is also a history of Glaucoma in my family and I also played with Spirograph, but I do not have astigmatism.
Yep. Same here. Kalidascopic purple and green patterns (always purple and green. No idea as to why). Unlike others, though, my family and I have pretty much always had fantastic eyesight.
OK, so maybe we’re developing a pattern here: glaucoma-prone Spirograph players. But frankly, I’m not hopeful for a research grant.
These patterns are called endoptic patterns. They can be seen inside the closed eye and are also known as ‘cognitively archetypical endoptic patterns’.
Because similar patterns have been found painted on cave walls all over the world, some archaeologists believe that widespread creative or shamanistic practices involve looking at these patterns, perhaps in the dark or in trance-like states, and then painting what they see.
here for instance
The odd thing for me is that, although the images are undoubtedly colourful, I would have a great deal of trouble describing the colours; the best thing I can liken it to is when you look at a bright light and get a coloured blind spot in your vision, except it isn’t really coloured at all because you can’t see anything in that region, but it has a sort of colour to it…
Cool, I’m a shaman. Bring me your weed and virgins. I’ll be in the sweat lodge.
eburacum, thanks, that’s the closest I’ve seen to an explanation. At least it gives me something to search for.
Magnetout, I have a guess about the feeling you described (which I am also familiar with). It could be that the reason the colors are difficult to describe is that the red, blue, and green cones in your eyes are detecting signals in a way that does not correspond to any natural color (given the sensitivity as a function of frequency for the three cell types, only certain combinations are normally possible). Thus while you get an impression of “colored,” it does not correspond to any color in your experience.
I suspect that this could be something like what a colorblind person would experience if his or her condition were somehow cured, or how a normal person would feel gaining a new color receptor.
I’m lucky enough to have never suffered a migraine, but I have come very close to fainting from lack of oxygen several times in my life. My vision narrows to a tunnel, and I can see weird geometrical patterns and colors around the outside. The predominant color for me feels like brown, but there’s a hint of the weird effect you get when your two eyes see the same thing with different colors due to 3D glasses or the like.
<i>endoptic patterns</i>
Entoptic with a t. Don’t worry, JonScribe - you’re talking about a universal human experience. If you find them easy to induce, you are indeed a potential shaman! Do a Google search on “flicker phosphenes”. Related article here - and see the site for this device, the Day Dreamer, that uses the effect of strobing as you describe to induce phosphene effects.
Thanks ray, that would appear to be what I’m seeing. But with my luck, John Ashcroft will now find a way to make it illegal.
‘Entoptic with a t’
Aha! no wonder I couldn’t find it on Google!
An archaeologist of my acquaintance introduced the term to me, but I must have filed it in the wrong mental pigeonhole:)