Bright Sight

Oliver Backhouse, Consultant Eye Surgeon www.cataract.org.uk

Visual Snow

Visual snow is often difficult to describe and patients can liken it to the ‘static fuzz’ seen on television screens. It is a non-specific symptom which may have many causes although usually none is found. Sometimes another unrelated eye condition draws ones attention to this symptom which is actually present in most of us if we concentrate on the ‘floaters’ of our eyes. They are most easily seen through closed eyelids while looking at a bright light (eg bulb, microscope). The noticing of these otherwise benign objects is called an Entopic phenomena.

Visual snow can occur in a variety of ophthalmologic disorders that can be diagnosed by the presence of additional clinical signs and symptoms. Such causes would include migraine, hallucinogenic drugs, immune disorders of the retina and rarely problems of the optic nerve and brain. For this reason a full detailed eye examination is needed along with electrical studies looking at the cellular health of the retina and imaging of the visual pathway in the brain with an MRI scan. It should be restated that most cases are completely benign in heir nature and are more commonly seen in people who are under stress / anxiety for whatever reason.

There currently is no established treatment for visual snow if no obvious cause has been found apart from ressurance that this is a common and usually benign symptom. There is little role for medication to ‘treat’ the symptoms. Occasionally cognitive behavioral interventions that focus on coping with the condition may help.