Visual Snow for beginners!

Think back to the days of analogue TVs.  Particularly the little one you had in your bedroom as a kid (or as a student), which had no connection to the outside aerial. Fiddling with the mini indoor aerial you had perched on top of your TV, trying to get a decent picture but not able to fully get rid of the static. Well, that’s visual snow. But not on your TV screen, in your eyes, whether they are open or closed.

(Picture taken from

Well, in your vision to be precise, as most VS (visual snow) sufferers pass eye examinations with flying colours.

I have had VS since I was 17. As far as I remember, it appeared from nowhere. I don’t remember feeling particularly stressed beforehand, or suffering from a particularly bad headache or migraine.

An ophthalmologist gave my eyes a thorough examination, which I passed with no trouble. It was during this examination I discovered that when closing or covering one eye, the vision in the other eye was fading to black and back again repeatedly. Fixing my gaze on one spot for more than a couple of seconds would cause everything to fade to black, and moving my focus would then bring it back. I have since (almost beyond doubt) determined that this is caused by my brain trying to focus my vision on my closed/covered and open eye at the same time. I discovered this by covering one eye with a sheet of white paper instead of my hand, and in this scenario my vision fades to white rather than black.

The ophthalmologist put my symptoms down to stress or simple migraine or something, leaving me feeling like a foolish hypochondriac, and too scared to return or seek a second opinion, even when my symptoms did not improve.

Fortunately my symptoms didn’t get worse for many years either, so although I couldn’t forget about them, I stopped worrying about my eyesight. It was only two years ago in 2012 when I noticed a change. It was also at the time when I realised I’d had a bad tooth infection for many months (don’t ask). As you can see, you can end up a hypochondriac, analysing every symptom, medication, food and activity you encounter, due to a lack of explanation.  Anyway, I digress.

My new symptoms in 2012 started when I lost sensation in my right little finger. When it did not return after several days, I saw my GP. She said due to the location, it was probably a trapped nerve and to come back if it didn’t get better. It didn’t. Over the following days, the numbness spread up my arm and onto my back. It was just the skin though, and didn’t cause any loss of function. The most scary symptom then arrived, though. I developed several small blind spots (Scotoma) in each eye. Thankfully they didn’t seem to overlap so my vision was fine with both eyes open. At a similar time, I seemed to develop BFEP (see pic below). This is normal to some extent, but is often severe in VS sufferers. Fortunately I have now learnt not to focus on it much of the time.

(Picture taken from here )

All of these symptoms except the VS, BFEP and Scotoma got better over the following months, but have made their appearances a couple of times since then, for one or two weeks at a time.

Without knowing the cause of VS, I can’t say whether or not these other symptoms are related to visual snow. I am lucky; some VS sufferers also have other debilitating symptoms that I have fortunately avoided so far. These include tinnitus, severe after images, depersonalisation/derealisation and loss of contrast or changes to visual colours, amongst others.

But it’s not all doom and gloom. Schankin C.J. et al. (2014)* have recently had their research into VS published. They took a sample of VS sufferers and surveyed them about their symptoms and whether they had a history of migraine. In a comparison with healthy participants, they found increased metabolism in certain areas of the brain (the right lingual gyrus and the left cerebellar anterior lobe adjacent to the left lingual gyrus) in VS sufferers.   

This research has made a significant dent in the world’s ignorance of VS, but this is just a start. Further research is needed both to back this study up, and to further our knowledge of this condition. Then, maybe, we can begin to dream of a cure in the future.

*Schankin C.J. et al. (2014). The Relation between Migraine, Typical Migraine Aura and “Visual Snow”. Headache: The Journal of Head and Face Pain.
Volume 54, Issue 6, pages 957–966, June 2014.

Click here for the link to the research article.

Click HERE to visit the EyeOnVision Foundation website, where you can donate towards visual snow research.

Alternatively you can donate HERE on the fundraising page 🙂


Chiari I Malformation

Has anyone heard of this? I found out about this online and it seems to match a lot of my symptoms, such as the vision loss, dizziness, numbness and headaches at the base of the skull (feel kind of like lumbar puncture headaches), which appear in particular when sitting or lying in certain positions. Perhaps it would even explain the heart palpitations.

The only thing is, I have already had an MRI and it wasn’t spotted on that. But then it wasn’t looked at by a specialist. Also, the lumbar puncture I had last year did not suggest high CSF pressure. Maybe I’ll ask my doctor about it anyway.