EFFECT OF PATTERN GLARE AND COLORED OVERLAYS ON A SIMULATED-READING TASK IN DYSLEXICS AND NORMAL READERS

Scotopic sensitivity syndrome or the Irlen syndrome describes symptoms of asthenopia and anomalous visual performance experienced while read ing that are lessened by colored filters. One putative explanation for this condition relates to pattern glare: a hypersensitivity to repeti tive patterns, including lines of print on a page. Experiment 1 used a placebo-controlled paradigm to investigate the effect of pattern glar e and colored overlays on performance at a simulated reading visual se arch task. Despite the fact that the subjects were university students , the results showed a tendency, of border-line significance, to suppo rt the conclusion that colored filters seem to improve reading through ameliorating pattern glare. In experiment 2 we compared the prevalenc e of pattern glare in matched groups of dyslexic children and good rea ders. The dyslexic group reported more pattern glare, but also reporte d more glare from a control stimulus. Pattern glare in the dyslexic gr oup was directly correlated with flicker sensitivity. The results are related to recent research on visual processing and ocular-motor funct ion in dyslexia.