It's extremely odd- one's visual field (at least in our cases) steadily contracts, until there's just nothing left. It's not an annulus of darkness closing in, it's juts nothing- the field you can see is smaller, and there's still nothing outside of it, just like there always isn't.
This is the first time I've heard of anyone else experiencing this phenomenon besides myself. Have there ever been any long-term effects on you?
Mine is slightly different. I don't have migranes, for one. Also, in addition to experiencing exactly what you described (minus the migrane), sometimes I experience the inverse: I can no longer see whatever I look at, but I retain peripheral vision. For example, if I were to look at the "o" in the word "for," I wouldn't be able to see the entire word. I could still read, with difficulty, until the effect became so strong that reading was impossible. (I still had peripheral vision, sort of, but eventually paragraphs became unseeable rather than individual words.)
Whenever any of these things occurred, I was completely normal again within two hours. It was bizarre, and it's mystified myself and two eye doctors. It's only happened less than a dozen times, but it's been happening since I was very young, and my most recent was less than a year ago.
The "blindness" was exactly as you describe: not a blackness, but a nothingness.
Do you happen to have any more info about the condition? It's very elusive.
It's a grab bag of weird perceptual effects that can precede migrane attacks (and apparently epileptic seizures), and they can be very disconcerting if you don't know about them.
In my case (only had them once or twice), I experienced the same visual field disassociation as you did (in addition to the scintillating scotoma thing) - I could see individual things in my field of view just fine, but I could not properly combine the whole scene into a whole. Like looking at a cubist artwork - each part is reasonable but the whole doesn't fit together, or had parts missing (not holes, just discontinuities). Of course, very shortly after that started, the migrane headache arrived.
Might want to consider talking to a doctor about it; while AFAIK auras are harmless if a bit scary, if you don't have them associated with a known issue like migrane headaches, might be good to try to find out where they're coming from. Not that anyone really seems to understand the mechanisms involved.
I get the blindness aura thing just before I have a migraine (which doesn't happen much anymore since I stopped accidentally suffocating myself with my pillow..).
The experience for me is absolutely identical to that of a blind spot optical illusion, except bigger and in a different area (just a bit off from the center). It's not generally obvious that there's an issue, the brain fills it in, but if I put text in that part of my vision I'll notice I can't actually read it.
I suffered something similar, just once, about twenty years ago, in high school, and never since. Although, instead of an impression of nothingness, it felt more like a Photoshop content aware fill, similar to the optic nerve blind spot, but moved to the fovea.
I was walking the hall to my first period, mainly looking at the bland floor tiles, and didn't realize anything was abnormal. When I happened to look up at the faces of fellow students, I noticed they had no faces, just skin colored smoothness. My hands, and text on the posters on the walls appeared in my peripheral vision, but as soon as I looked directly at anything, it seemed to disappear into an average of it's surrounding colors. I didn't freak out, but calmly walked to my first period, where I was scheduled to take a test. I made way to my desk, and marveled at this oddness, but didn't say anything, until the test was passed out and I could tell it was a page of text, but, of course, the words disappeared upon inspection. I was really impressed how useless my peripheral vision was in dealing with text or faces.
I had an awkward conversation with the teacher, who I feared thought I'd invented a disorder to get out of the test, before being allowed to visit the nurse.
The condition lasted maybe an hour. The ophthalmologist I saw shortly after found nothing wrong with my retinas or eye pressure, and declared it a visual migraine and let me go, with a newfound empathy for those with macular degeneration.
The content-aware fill is what I get as well -- I have some permanent blind areas in my right eye due to optic nerve damage; I lost a lot of peripheral vision, but also the normal optic nerve blind spot is quite a bit larger in that eye -- about 1/4 of the height of my visual field, and half as wide -- fortunately still not affecting the central point of focus.
Obviously no black patch or anything like that; I first noticed the missing section (before I had visual field tests done to detect it properly) while driving, stopped at a light; I rubbed my other eye momentarily, and the traffic light vanished.
I also suffered something similar on multiple occassions in my late 20s and early 30s - growing rainbow zig-zags accompanied by graduals loss of vision in both the center of my field of view and edges of my peripheral vision, although never to the point of total blindness. Incidents would last between one and two hours. But, after several ophatmologist and visits to other physicians, I finally found the trigger: it happened roughly 18 hours after consuming 2 or more glasses of absinthe. Stopped drinking absinthe, haven't had an aura in years.
I'm sorry to hear that. My wife has a rare brain disease and unfortunately, it's something she's all too familiar with. If it's happening to you without corresponding migraines (or even with), see a neurologist, there may be something wrong. Her neurologist regularly sends her for opthalmologist exams just in case and they never find anything wrong.
Hey, I had that about twenty years ago. The only symptom I had was that I would wake up with a headache for no apparent reason (not a migraine, but frequently nausea-inducing).
My ophthalmologist detected it during a regular examination and sent out for MRI/CAT scan/spinal tap to rule out everything else, then put me on a regimen of -- oh, now I can't remember; the medicine used for altitude sickness (diamox?) and eventually "cured" me; I haven't had a recurrence since.
I guess my point is that the grandparent poster should consider seeing an ophthalmologist and/or a neurologist at their earliest convenience. (My doctor was pleased that he'd "caught it in time"; he spoke of another patient in which it had not been detected quickly enough and that person had gone blind.)
You mentioned "eye doctors," but have you seen a retina specialist? I've temporarily lost sight twice, but in my case it is like having matte grey construction paper cover part or all of my vision. My retina specialist has found a couple of issues.
No long-term effects that I know of, aside from the simple on-going fact that I have migraines; they didn't get any worse or more frequent after that, nor have I since developed any other visual or neurological symptoms. As it happens, I don't get migraines very often- once or twice a year. My wife & mother both get them on a much more regular basis, once or twice a month.
The loss of foveal vision or random patches of the visual field (as opposed to gradual-leading-to-total elimination of the entire visual field) is something I have encountered a few times. As quantumet noted, auras are kind of a grab-bag, different people can have wildly different kinds of visual distortions, and some migraine sufferers don't have them at all. I know one who gets aural (hearing) distortions instead; meanwhile, I don't get any hearing issues, and my wife becomes hypersensitive to sound but doesn't experience distortion.
Migraines, generally, like seizures, are a result of mis-fires in your brain (super simplified explanation, of course). Essentially, something goes wrong such that your brain just decides that it is in pain for no particular reason (although there are triggers, just like there are triggers to epilepsy, that set of just the wrong cascade of neurons). Auras are just another manifestation of the same thing- if the thing that goes wrong goes wrong in or near your visual cortex, you get visual distortions in addition to the pain. Eventually, your brain resets, and then things are normal again, until your brain (metaphorically speaking) tries to read out-of-bounds memory, or goes into an infinite loop, or whatever else it is (again as quantumet noted, the exact mechanism is not really all that well understood), the next time.
Side note, on how everybody's auras are a little different- we just found out about a month ago that my most common aura is blue sparkles, while my wife's is gold sparkles. We knew that we both commonly saw sparkles, just never happened to mention the color before. Also incidentally, I do get auras much more often than I progress to a full-blown migraine headache.
Since the problem is neurological, eye doctors generally won't be able to figure it out or do anything about it. Generally, because eye problems can be migraine triggers. My wife starts getting headaches if she leaves her glasses off too long, and one of the first things to check when migraine frequency increases is whether her prescription has gone out of date. Other triggers are dehydration (for her) hunger (for both of us; this is a problem for me because I don't get hungry normally, so sometimes the first indication that I need to eat today is the onset of a headache) and sleep deprivation (for both of us).
Some of the migraine aura symptoms are terrifying. My ex temporarily lost the ability to remember most words, including "door". Even after being told them, they were gone again seconds later.
This is the first time I've heard of anyone else experiencing this phenomenon besides myself. Have there ever been any long-term effects on you?
Mine is slightly different. I don't have migranes, for one. Also, in addition to experiencing exactly what you described (minus the migrane), sometimes I experience the inverse: I can no longer see whatever I look at, but I retain peripheral vision. For example, if I were to look at the "o" in the word "for," I wouldn't be able to see the entire word. I could still read, with difficulty, until the effect became so strong that reading was impossible. (I still had peripheral vision, sort of, but eventually paragraphs became unseeable rather than individual words.)
Whenever any of these things occurred, I was completely normal again within two hours. It was bizarre, and it's mystified myself and two eye doctors. It's only happened less than a dozen times, but it's been happening since I was very young, and my most recent was less than a year ago.
The "blindness" was exactly as you describe: not a blackness, but a nothingness.
Do you happen to have any more info about the condition? It's very elusive.