Arabic Reading Performance With a Chromatic Acuity Chart.

Area of Science:

• Ophthalmology
• Visual Perception
• Human Factors

Background:

• Reading performance is influenced by text contrast.
• Chromatic contrast's role in reading, especially for Arabic text, requires further investigation.
• Establishing baselines is crucial for diagnosing visual impairments like red-green color vision loss.

Purpose of the Study:

• To compare reading performance in Arabic text using chromatic (red-on-green) versus achromatic (black-on-white, gray-on-gray) contrast.
• To assess the impact of chromatic contrast on reading speed and accessibility in normally sighted individuals.
• To establish a baseline for identifying selective red-green chromatic sensitivity loss.

Main Methods:

• Evaluated reading performance using maximum reading speed (MRS), reading acuity (RA), critical print size (CPS), and Reading Accessibility Index (ACC).
• Utilized three near-point charts: Balsam Alabdulkader-Leat (BAL) black-on-white, red-on-green, and gray-on-gray (matched background luminance).

Main Results:

• Maximum reading speed (MRS) was similar across all charts, though slightly higher for red-on-green. Reading Accessibility Index (ACC) was lower for the black-on-white chart.
• Reading acuity (RA) was better and critical print size (CPS) smaller for the black-on-white chart compared to chromatic and gray charts.
• Individuals with red-green deficiencies showed poorer RA and larger CPS on the red-on-green chart versus achromatic charts.

Conclusions:

• While chromatic contrast showed statistically significant differences in MRS and ACC, these were not clinically significant for normally sighted individuals.
• Similar MRS across charts supports findings that reading speed plateaus when contrast is well above threshold.
• Lower RA and larger CPS for chromatic/gray charts were attributed to reduced background luminance and contrast, highlighting potential diagnostic value for color vision assessment.