visual snow syndrome

This is a rare neurological condition which remains a mystery to medical practitioners.  The symptoms are visual disturbance often accompanied by brain fog and tinnitus.  It follows a bout of a virus, a concussion, a pregnancy or a migraine.  It is as if the sufferer is seeing the world through a black and white pattern, rather like the static on an old TV.  Tests reveal nothing wrong with the eyes or the brain, and yet the snow persists.

VSS has now been recognised as an illness by the WHO which is reassuring to those who experience it because it had been hard sometimes to persuade people that their symptoms were real.  This might also lead to further research and the discovery of the cause.