Irlen syndrome

Irlen syndrome (or scotopic sensitivity syndrome) is a hypothetical medical condition of disordered visual processing which, it is proposed, can be treated by wearing colored lenses. The ideas of Irlen syndrome are pseudoscientific and not supported by scientific evidence, and its treatment has been described as a health fraud taking advantage of vulnerable people.

The condition was proposed in the 1980s.

Irlen method
The Irlen method uses colored overlays and tinted lenses in the form of glasses or contact lenses. The method is intended to correct visual processing problems; it is claimed the resultant retiming of visual signals in the brain improves symptoms associated with Irlen syndrome.

History
In 1980, New Zealand teacher Olive Meares described the visual distortions some individuals reported when reading from white paper. In 1983, while working under a federal research grant at the California State University of Long Beach, American psychologist Helen Irlen thought that filtering the visual information before reaching the brain through the use of either colored overlays or spectral filters (worn as glasses), could allow the brain to correctly process the visual information it received. They thought that in doing so, these colored overlays and spectral filters could eliminate symptoms associated with Irlen syndrome. Similar symptoms were separately described by Meares and Irlen, each unaware of the other's work. Irlen, who was the first to systematically define the condition, named the condition "scotopic sensitivity syndrome," though in years following, some referred to it as Meares-Irlen syndrome, Irlen syndrome, and visual stress.

Early studies investigating Irlen syndrome as a treatable condition have been criticized for having a biased and subjective approach to their research.