Understanding the causal mechanisms of visual processing problems: A possible biochemical basis for Irlen syndrome?

Abstract

This paper discusses potential causes for the visual‐perceptual dysfunction known as Irlen Syndrome (IS), and describes a preliminary investigation into the possible biochemical basis for this dysfunction. A review of studies revealed that there is a sub‐group of people with chronic fatigue syndrome (CFS) who have visual‐perceptual problems similar to those identified as IS, and specific biochemical anomalies have been identified for CFS. This investigation found a variety of biochemical anomalies in 143 subjects with CFS who had been identified on a questionnaire as likely to have symptoms of IS. It was suggested that the broad diagnostic categories currently in use, such as CFS, dyslexia and attention deficit hyperactivity disorder may include a range of overlapping clinical disorders. The analysis of biochemical anomalies in particular may be important in the development of more valid diagnostic categories and treatment strategies for these disorders, as it goes beyond observed behavioural symptoms to identify underlying (and possibly common) causal mechanisms.