RESUMO
PURPOSE: Colors have been shown to improve reading performance; however, the effect of colors on Arabic orthography has not been studied. This study aimed to design and create a chromatic acuity chart to evaluate the effect of chromatic contrast on Arabic reading performance. METHODS: Color selection for the newly developed chromatic acuity chart was based on the contrast between the L, M, and S cones. The colors were chosen to have a luminance of approximately 13.6 cd/m2 with red text on a green background. A Pantone color guide set was used to choose the colors. Fifteen healthy individuals aged 19-27 years were recruited. Reading performance was measured using the newly developed red-green (R-G) chart and compared with the original achromatic Balsam Alabdulkader-Leat (BAL) chart with a luminance of 95 cd/m2. The outcomes were maximum reading speed in standard-length words per minute (SLWPM), reading acuity (RA), and critical print size (CPS). RESULTS: The mean R-G SLWPM of 201 wpm was similar to that of the BAL chart (P < 0.05). The mean RA for the R-G chart was - 0.05 logMAR and - 0.20 logMAR for the BAL chart (P < 0.05). The CPS for the R-G chart was 0.36 logMAR, significantly higher than the original chart of 0.17 logMAR (P < 0.05). CONCLUSION: This study showed that the reading performance for a text that varies only in chromatic contrast along the R-G axis reduces the reading performance for CPS and RA. Individuals showed an approximate decline of two lines on an Arabic continuous text chart compared with a high-contrast achromatic chart. This information can be used to further develop a set of near-reading charts that can efficiently determine whether there is a differential loss in chromatic and achromatic sensitivity in patients with various vision disorders.
