MYALGIC ENCEPHALOMYELITIS /CHRONIC FATIGUE
Recent research in Australia has found that individuals with ME/CFS report remarkably similar symptoms to those reported by individuals with visual stress.  A research team from the University of Leicester Department of Neuroscience, Psychology and Behaviour has examined patients with CFS and found that those suffering from the condition are more vulnerable to pattern-related visual stress.  
Visual stress causes a cluster of symptoms including cognitive and physical fatigue, headache, balance issues (resulting from perceptual distortions in the environment), and discomfort when viewing repetitive striped patterns in the environment and in text, symptoms that are alleviated with the use of precision tinted lenses. Clients referred to Opticalm for migraines and post-concussion vision issues often report headaches and fatigue, both physical and cognitive. After wearing their precision tinted lenses these clients have commented that they no longer have their headaches and have more energy and can think more clearly (less physical and cognitive fatigue)
This would seem to indicate that it is important to investigate visual stress when Chronic Fatigue is diagnosed to rule out and treat visual stress if it is contributing to symptoms.
 Loew SJ, Marsh NV, Watson K. Symptoms of Meares-Irlen/Visual Stress Syndrome in subjectsCFS) diagnosed with Chronic Fatigue Syndrome. International Journal of Clinical and Health Psychology. 2014:14-2:87-92