Irlen syndrome: systematic review and level of evidence analysis.

Background: Scotopic sensitivity syndrome, later called Meares-Irlen syndrome or simply Irlen syndrome (IS) has been described as symptoms of poor reading ability due to poor color matching and distorted graphic images. Individuals with this syndrome are considered slow, ineffective readers with low comprehension and visual fatigue. It is still uncertain whether the disease pathophysiology is an independent entity or part of the dyslexia spectrum.