How can visual perceptual distortion be spotted?
Visual perceptual distortion should be suspected in children who have trouble learning to read, particularly if they report headaches and eye-strain from prolonged exposure to the page. If the child reports any illusory movement of the letters or words, or glare from the white paper, then treatment with coloured overlays or filters should be considered. One possible question to ask is: “After you have been reading for a while, do the words or letters do anything different?”. If open-ended questions such as the above fail to provoke reports of distortions, more direct questions can be given. The child can be shown a page of text, and asked the following questions: “Do the letters stay still or do they move?”; “Are the letters clear or are they blurred?”; “Is the page too bright, not bright enough or just about right?”. Reports of movement, blurring and glare are more likely in children who benefit from overlays.
