Refractive error and the reading process: a literature analysis.

The literature analysis of refractive error and reading performance includes only those studies which adhere to the rudaments of scientific investigation. The relative strengths and weaknesses of each study are described and conclusions are drawn where possible. Hyperopia and anisometropia appear to be related to poor reading progress and their correction seems to result in improved performance. Reduced distance visual acuity and myopia are not generally associated with reading difficulties. There is little evidence relating astigmatism and reading, but studies have not been adequately designed to draw conclusions. Implications for school vision screening are discussed.