A systematic review of controlled trials on visual stress using Intuitive Overlays or the Intuitive Colorimeter
Evans, Bruce J.W.
Allen, Peter M.
- Publisher: Elsevier BV
Journal of Optometry
(issn: 1888-4296, vol:
PRVS, pattern related visual stress | Colorímetro | Revisión | RCT, randomised controlled trial | Visual stress | Coloured overlays | WRRT, Wilkins Rate of Reading Test | Colorimeter | Estrés visual | IO, intuitive overlay | Review | VS, visual stress | PGT, pattern glare test | Optometry | IC, intuitive colorimeter | Filtros coloreados
mesheuropmc: genetic structures
Claims that coloured filters aid reading date back 200 years and remain controversial.\ud Some claims, for example, that more than 10% of the general population and 50% of people with\ud dyslexia would benefit from coloured filters lack sound evidence and face validity. Publications\ud with such claims typically cite research using methods that have not been described in the\ud scientific literature and lack a sound aetiological framework.\ud Notwithstanding these criticisms, some researchers have used more rigorous selection criteria\ud and methods of prescribing coloured filters that were developed at a UK Medical Research\ud Council unit and which have been fully described in the scientific literature. We review this\ud research and disconfirm many of the more extreme claims surrounding this topic. This literature\ud indicates that a minority subset of dyslexics (circa 20%) may have a condition described as\ud visual stress which most likely results from a hyperexcitability of the visual cortex. Visual stress\ud is characterised by symptoms of visual perceptual distortions, headaches, and eyestrain when\ud viewing repetitive patterns, including lines of text. This review indicates that visual stress is distinct\ud from, although sometimes co-occurs with, dyslexia. Individually prescribed coloured filters\ud have been shown to improve reading performance in people with visual stress, but are unlikely\ud to influence the phonological and memory deficits associated with dyslexia and therefore are\ud not a treatment for dyslexia.\ud This review concludes that larger and rigorous randomised controlled trials of interventions\ud for visual stress are required. Improvements in the diagnosis of the condition are also a priority.