Chronic Fatigue Syndrome (CFS) or Myalgic Encephalomyelitis (ME) is a debilitating disorder, affecting at least 250,000 people in the UK. Marked by debilitating fatigue, its aetiology is poorly understood and diagnosis controversial. A number of symptoms overlap with other illnesses with the result that CFS/ME is commonly misdiagnosed. It is important therefore that significant clinical features are investigated. People diagnosed with CFS/ME consistently report that they experience vision-related symptoms associated with their illness1-3 with some of these reports being verified experimentally. Although vision-related symptoms may represent a significant clinical feature of CFS/ME that could be useful in its diagnosis, they have yet to be included in clinical guidelines
