Floaters, visual snow syndrome and blurry vision

Hoopoe

Hoopoe

Senior Member (Voting Rights)
I read about this syndrome because I'm becoming light sensitive, can't see in poor light conditions and have intrusive visual snow and disturbances. The association between light sensitivity and ME/CFS is well known, I'm wondering how many others have some of these additional symptoms?

Visual snow is a neurological disorder characterized by a continuous visual disturbance that occupies the entire visual field and is described as tiny flickering dots that resemble the noise of a detuned analogue television. In addition to the static, or “snow”, affected individuals can experience additional visual symptoms such as visual images that persist or recur after the image has been removed (palinopsia); sensitivity to light (photophobia); visual effects originating from within the eye itself (entoptic phenomena) and impaired night vision (nyctalopia).
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An exaple of visual snow:

cxjgjyzklbmpl1hydpit.jpg

Another example
Visualsnow-80.jpg

An example of entoptic phenomena:



The afterimages in this syndrome are different from the normal afterimages that everyone has. Normal afterimages occur only when staring at a high contrast image and are in complementary color. An example of abnormal afterimages:



(I don't have these abnormal afterimages)

In addition to this, there is also light sensitivity and difficulty seeing at low light conditions.

There appears to be some evidence this is a brain problem rather than an eye problem.

A neuroimaging study using [18F]-FDG PET seems to have confirmed these hypotheses. The study demonstrated, in patients affected by visual snow, a hypermetabolism of the lingual gyrus (9); this is an area of the visual cortex involved in several other conditions such as photophobia. The lingual gyrus is also a key element of complex physiological functions such as visual memory, perception of color and identification of facial expressions.
Visual cortical hyperexcitability (10, 11) and thalamo-cortical dysrhythmia (12) have also been hypothesized as possible causes for the pathophysiology underlying visual snow.
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https://rarediseases.org/rare-diseases/visual-snow-syndrome/
 
I've had floaters ever since I can remember and long, long before I got ME. I've had routine eye checks and eye health is fine.

I have always been sensitive to bright lights and certain lighting triggered migraines since about 20 years before ME onset.

About a decade ago my migraines changed and at the same time I started to experience this visual snow. Originally it was just on very bright days, but it can also happen on dull days. Wearing sunglasses helps but it can still be noticeable. Sometimes it's extremely distracting, at others barely there. I don't have it all the time. As this was new onset & because of the migraines I saw a neurologist. I was advised this was "migraine activity" in the brain even though it happened independently of any other typical migraine symptoms.
 
I have occasionally experienced the afterimage thing. It has seemed connected to the tail end of a viral infection, or otherwise being more run down than usual. It might have something to do with sleep deprivation.

Odder, for me, is "flickering vision," in which image brightness rapidly fluctuates like you're watching an old silent movie. Prior to the illness, I would sometimes see this for a few seconds when moving from a dark area to brighter area, or vice versa. It seemed to be part of adapting to very different brightness levels and I considered it normal. After ME, I had rare occasions where this kind of flickering persisted for 10 minutes or more while just standing outside. I'd never had that before.

This might also be an effect of a sleep deprivation. I think lack of sleep makes you more light sensitive if it goes on long enough, and enough accumulated "unrefreshing sleep" might do the same.
 
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I looked into the connection about 18 months ago when my visual disturbances started. You'll find some forum threads I started if you do a search on here. Another area that desperately needs looking into in more detail. The only work I saw on ME and vision was from Leicester and it didn't involve these sorts of disturbances.

One thing I did read about a lot was possible connection between visual snow / disturbances and tinnitus, another primary symptom for me. I found this framework for describing these phenomena interesting because I also suffer from OCD (https://en.wikipedia.org/wiki/Thalamocortical_dysrhythmia)

Oh and these issues are almost definitely brain rather than eye issues. Even floaters can be a brain issue - not being able to filter these shapes out.
 
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PS Thanks for posting the entopic phenomena video. I have this and didn't know it had a name! Like swirls of ink of slightly different hue moving around when my eyes are closed.
 
I was about to start a thread on this myself! Visual snow preceded by ME but has currently worsened along with my brain fog. I get tinnitus and ocular migraines too, both of which are apparently connected to visual snow.

I never realised it was a thing for years. I assumed that was just how the eyes interpreted points of light coming in on the retina and forming a picture. Since it's got worse, I've now realised it's obviously not.

Eye tests, etc, are all normal. Fatigue makes it worse but it's not blurriness. It's not definitely 'noise' in the image.
 
I have tinnitus too but didn't connect them. I've had tinnitus since young childhood. It started after I had both tonsils and adenoids out.

The blurring is definitely related to ME. As eye movement and focusing are controlled by muscles I've always assumed it's down to that. I have regular eye tests and make sure they know about it, but my eyes are healthy. I do have to be careful though as my pupil distance changes slightly when my eyes tire and that makes a big difference when they take their measurements for correction lenses.

Re. the visual snow type symptom - I also get burn out spots when it's bad. Like someone burning an old celluloid film from the back with a cigarette. The neuro reckoned it was all part of the same thing. In my case at least.
 
InitialConditions said:
I do get a slight bluriness on bad days. This is perhaps the only vision symptom that is an actual eye (or rather eye muscle) issue.
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I should say, I get blurriness when fatigued too, but the core visual 'snow' isn't that. I.e., it doesn't feel like I need glasses. I tried glasses and they gave me a headache without making a difference.

I suspect the blurriness is due to something getting tired and not focussing properly. But the visual snow seems to be there even without that.

The best way to describe it is as a poorly tuned in or grainy TV picture. Or an image with low resolution blown up too big. Or like the air is alive with innumerable tiny atoms that are naked to the eye somehow.
 
adambeyoncelowe said:
I should say, I get blurriness when fatigued too, but the core visual 'snow' isn't that. I.e., it doesn't feel like I need glasses. I tried glasses and they gave me a headache without making a difference.
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Like you, my eye muscle fatigue and "snow" occur independently. I need to wear glasses anyway and have done since before this all started. I find sunglasses can help reduce it and make less distracting.

Edit - though my shades have prescription lenses too.
 
thats exactly how i see, im sick for 5years now with cfs. And about after 2 years my sight worsened a lot and looks pretty much just like those pictures now
 
Moved posts

I still haven't seen anything about floaters and it's damn frustrating. Most of the vision issues are clearly neurological, but the damn floaters have to be observable, I don't understand how it takes so much time to do basic stuff like this.

They're reported quite a lot in LC. Seem to be a bit less with ME but in my case I easily have hundreds of them, they can't be that hard to see and study.
 
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rvallee said:
I still haven't seen anything about floaters and it's damn frustrating. Most of the vision issues are clearly neurological, but the damn floaters have to be observable, I don't understand how it takes so much time to do basic stuff like this.

They're reported quite a lot in LC. Seem to be a bit less with ME but in my case I easily have hundreds of them, they can't be that hard to see and study.
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I had thought the number of floaters an individual had were stable long term, rather the variable was how many the individual was consciously aware of. A few years ago (pre Covid-19) a friend discovered she had a rare heart condition, one of the symptoms she had been aware of was an apparent increase in floaters in her eye. Her consultant was emphatic that though her condition may have contributed to her increased awareness of the floaters the actual number of them would not have changed. What changes is the person’s visual system’s ability to suppress them as a conscious perception. At the time I did a web search and only found links that agreed with this.

Is there any evidence that this is not the case in Long Covid?
 
When I first got ME/CFS, I too noted lots of floaters. I did report it to my GP, but I think she thought I was just being hyper vigilant. I guess that's possible - I was trying to find clues as to what had happened. Over time, I ceased to be aware of them.

I too have heard that the brain is very good at filtering out the consciousness of floaters. There was that study where people were given glasses that turned the world upside-down, in terms of what people could see. I think all of the participants adapted to new view of the world within about two weeks - the brain inverted the visual signals and they saw the world normally again. So, definitely the brain can 'tidy-up' visual signals.

I don't know if there is a real increase in floaters upon ME/CFS onset, or if it's new hyper-vigilance relating to existing floaters, or if maybe the brain takes a while to get used to having less energy for editing the visual signal.
 
Just finding this thread, the description of visual snow is a revelation. I definitely get that, just like the picture.

I have previously talked about my visual symptoms as blurriness, which comes and goes. It got to be a major problem when driving. I could still drive safely, but I couldn't read street signs for navigation.

My optometrist checked my visual field with a test where you click when you can see dots around the visual field while keeping the eyeball still. I had "holes in my vision", the optometrist couldn't explain it. edit - They were a problem when I was reading. It would have been followed up, but I moved away from the city.

There are definitely things to do with vision in ME/CFS that deserve careful evaluation. Accurately describing the symptoms might give us clues as to what the cause(s) of the symptoms are.
 
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