Association between daily near-vision duration and visual symptom burden among university staff: a cross-sectional study

Background University staff routinely perform prolonged near-viewing tasks that may contribute to visual symptoms and work-related difficulties. We examined the associations of daily near-vision duration with Convergence Insufficiency Symptom Survey (CISS) score and of near-vision duration and CISS score with self-reported work impact. Methods This cross-sectional survey included 255 university staff members. Daily near-vision duration was analyzed per 2 h/day. Linear regression estimated adjusted mean differences in continuous CISS score, and modified Poisson regression estimated prevalence ratios (PRs) for CISS score ≥21 and self-reported work impact. Models adjusted for age, sex, education, work type, and survey year. Results The primary CISS models included 253 of 255 respondents. Among 228 respondents with an applicable work-impact response, the work-impact model included 226 complete cases. Mean CISS score was 22.7 (SD 10.9), 58.0% had a score ≥21, and 53.9% of respondents with applicable responses reported work impact. Each additional 2 h/day of near-vision duration was associated with a 1.79-point higher CISS score (95% CI 0.73–2.84) and a PR of 1.15 (95% CI 1.07–1.24) for CISS score ≥21. In the mutually adjusted work-impact model, the PRs were 1.03 (95% CI 0.95–1.12) per 2 h/day and 1.18 (95% CI 1.11–1.25) per 5 CISS points. Conclusion Longer daily near-vision duration was associated with greater visual symptom burden, and higher CISS score was associated with self-reported work impact. Assessing visual symptoms alongside near-work duration may help occupational health services identify staff who could benefit from eye examination and workplace assessment.