codeman38 and I have just created
visual_stress, for anyone who experiences symptoms of visual stress. It's also known as visual processing disorder, Meares-Irlen Syndrome, Irlen Syndrome, or Scotopic Sensitivity Syndrome, and it takes the form of unpleasant visual distortions or eyestrain when reading, sometimes with headaches or migraine as well. It's commonly treated with colour, for instance in the form of acetate overlays for paper or tinted spectacles. You can read more about it
here. There's a strong connection with dyslexia, and some people with processing problems have co-existing auditory processing disorder or other neurological issues.
You don't have to be diagnosed with visual stress to join, just to have difficulties in this general area. People with ME/CFIDS, migraine, MS, epilepsy, autism spectrum disorders or ADD/ADHD, for example, often experience visual problems of this nature.