This study investigated the effects on students identified with Scotopic Sensitivity Syndrome (SSS) or Irlen Syndrome (IS) when using colored overlays as an intervention (immediately and over time) to assess reading performance (rate, accuracy, and comprehension); to measure visual-motor integration; and to assess attitude toward reading. SSS/IS is a visual perceptual problem related to a collection of symptoms that affects an individual's performance when reading. Three participants, all males (one 3^rd-grade student, one 4^th-grade student, and one 5^th-grade student), were identified as having SSS/IS and other learning disabilities.

The study involved five test instruments (Irlen Reading Perceptual Scale, Qualitative Reading Inventory-4, Running Records, Visual Motor Integration, and Elementary Reading Attitude Survey), using pre- and post tests combined with a single-subject Alternating Treatment Design (ATD). Data were analyzed qualitatively through visual analysis of tables, line graphs, and bar graphs.

While this study showed inconsistent and mixed results for the use of colored overlays, there were some interesting positive effects in the area of attitude toward reading and in immediate effects on rate and accuracy. Results were inconclusive on the long term effects of the use of colored overlays over time. The lack of consistent results in this study suggests that there is not a clear clinical significance for the use of colored overlays.