The effect of colored overlays on reading in patients with acquired brain injury

To investigate if colored overlays influences reading performance in adults with an acquired brain injury (ABI).

An experimental cross-sectional study where patients with ABI and reading-related visual discomfort (n = 25) were recruited from an outpatient rehabilitation clinic. Reading speed with and without colored overlays was investigated using the Wilkins Rate of Reading Test (WRRT) and coherent text. Eye movements were recorded with the Readalyzer. The Visual Discomfort Scale (VDS) was used for symptom assessment.

Reading of WRRT was faster with an overlay (3.9%, p = 0.04). Participants with lower baseline reading speed (without overlay) showed greater improvements when reading the WRRT (median increase 10.9, 4.6-67.0%) and coherent text (median increase17.5, 5.5-93.2%). Improvements were reflected in significantly fewer progressive and regressive saccades, and shorter fixation durations. Improvements in reading speed correlated positively with VDS score (p = 0.05).

The findings support the theory that colored overlays can facilitate reading in some patients. Possible mechanisms are discussed in relation to reading ability, visual, and cognitive functions. Further research will be needed to increase the understanding of sensory visual stress and the effect of colored overlays in the ABI population.