Reading between the lines of visual discomfort and Myalgic Encephalomyelitis (ME) and Chronic Fatigue Syndrome (CFS)

ME/CFS is a debilitating disorder affecting at least 250,000 people in the United Kingdom. This condition has a number of incapacitating symptoms including post-exertional fatigue, cognitive deficits, and flu-like symptoms. However, with an unresolved aetiology, controversial diagnosis, and no clear treatment, it is important that potential clinical features are identified and explored. Visual symptoms are often reported by patients, and, there is now a growing body of literature to experimentally support this. Nevertheless, there is a paucity of research investigating precisely how these visual symptoms impact the everyday lives for those with ME/CFS. This is especially the case for reading activities. The aim of the experiments within this thesis was to thoroughly investigate vision-related reading in ME/CFS patients. The results show that vision related reading discomfort in ME/CFS is unlikely to be a factor of impaired ocular motor function in reading, or, a poorer reading acuity. However, ME/CFS patients did demonstrate elevated levels of pattern-related visual stress. Given that text is spatially reflective of patterned stimuli that can induce visual stress distortions in those who are susceptible, this may account for some of the visual symptoms that are experienced during reading in those with ME/CFS. These findings are discussed in relation to possible therapeutic interventions and it is suggested that future, more direct, research is required in order to augment the findings.