Transient and sustained processing: effects of varying luminance and wavelength on reading comprehension.

BACKGROUND: Reading disability (RD) is a serious epidemiologic problem and may affect up to 15% to 20% of elementary school children. This study addresses whether the reading comprehension skills of children with RD improve as wavelength and contrast of light are altered. METHODS: Fifty-six children, identified as either normal or reading disabled, were required to read a series of standardized 300-word passages under four conditions: no filter (baseline); light gray filter, dark gray filter, and blue filter. Each reading selection was timed, reading comprehension was measured, and data were processed. RESULTS: Initial standardized reading comprehension test scores significantly differentiated average from poor readers. Using reading selection levels consonant with each subject's ability, no significant differences were measured in baseline comprehension scores between good and poor readers. Comprehension scores of poor compared to good readers were significantly better using blue filters (p < 0.01). CONCLUSIONS: Our study suggests an association between wavelength of light, luminance, and reading performance. Blue filters were found to improve reading comprehension in poor readers. The results support the concept of a transient system deficit involving wavelength of light and reading performance.