Predicting the continued use of overlays in school children--a comparison of the Developmental Eye Movement test and the Rate of Reading test.

Coloured overlays have been advocated to enhance reading speed and ability in children with reading difficulty or dyslexia. Assessing the efficacy of overlays has to date been largely subjective. Objective assessment is presently carried out with the Rate of Reading test (RRT), where an increase in reading speed of more than 5% is considered to indicate a positive prognosis for continued use of the overlay. The Developmental Eye Movement (DEM) test is used to assess horizontal scanning behaviour in a number naming task. In this study both tests were utilised to determine whether coloured overlays could enhance reading performance or scanning. This article shows that for some children rate of reading is not improved with coloured overlays although performance on the DEM test does improve. Improvements to the DEM scores occurred in 88% of children who continued to use overlays for more than 3 months. This compared with 60% sensitivity in the RRT. The possible reasons for this phenomenon and the clinical implications are discussed.