Development of Automated Visual Acuity Measurement Using a Calibration-Free Eye-Tracking System

Purpose Infant vision assessment often relies on grating acuity; however, its objectivity and convenience must be improved. A calibration-free eye-tracking system, even in preverbal children, enables easy and precise gaze analysis. This pilot study aimed to develop a reliable automated monocular vision screening. Methods Participants (n=118) underwent a grating visual acuity test using the eye-tracking system. Correlations between the grating acuity, uncorrected visual acuity, and refractive error were analyzed across different cutoff values of fixation duration percentage. Results Strong correlations were found between the grating acuity and refractive error at 69% and 88% thresholds. Similar correlations with uncorrected visual acuity were noted at 70% and 89% thresholds. False-negatives around the 70% threshold were noted, indicating potential overestimation of acuity in cases of low visual acuity/high refractive error. Discussion The results highlight the feasibility of calibration-free eye-tracking system-based monocular vision screening with an optimal screening threshold of 90%.