Contrast sensitivity and binocular visual functions in Chinese college students with mild and moderate myopia

Abstract

To compare binocular visual functions (i.e., accommodation, vergence, and contrast sensitivity) among Chinese university students with emmetropia, mild myopia, and moderate myopia. This study enrolled 104 visually normal Chinese volunteers, who were categorized into three groups according to their refractive status. Binocular visual functions were assessed, including accommodation and vergence facility, sensory fusion, and binocular contrast sensitivity functions (CSFs). After controlling for age and sex, generalized linear model (GLM) analyses indicated that refractive error category significantly predicted AULCSF (Wald χ² = 8.158, P = 0.017). Relative to the emmetropic group, both the mild myopia group and the moderate myopia group showed significantly higher AULCSF values (both P < 0.05). Further analysis across low-, mid-, and high spatial frequencies revealed a significant group difference at 6 cycles per degree (Wald χ² = 8.433, P = 0.015). No significant differences were observed in other binocular visual function parameters—including heterophoria, accommodation, vergence, and positive/negative fusional convergence—across the three refractive groups. Mild and moderate myopic adults had slightly better binocular CSFs than emmetropic participants under medium spatial frequency, despite the unclear reason behind it. Not applicable.