Social jet lag and visual acuity decline in junior high students: a retrospective cohort study

Reduced visual acuity, defined according to the Technical Standard for Physical Examination for Students (GB/T 26343 - 2010) as unaided distance visual acuity below 5.0 on the 5-grade notation scale (equivalent to LogMAR ＞ 0.0), affects more than 40% of junior high school students in China. Lifestyle factors have been implicated in refractive development; however, the role of social jet lag remains unclear. We examined the association between large social jet lag, defined as a sleep midpoint discrepancy exceeding 1 h between school and leisure days, and incident visual acuity decline over one year. In this retrospective cohort study, 903 students from 2 junior high schools in Yangzhou, China were included. Baseline lifestyle-related information was extracted from pre-2020 records. Initial visual acuity was assessed in 2020, with follow-up assessment in 2021. Incident visual acuity decline was defined as a deterioration of at least 1 acuity grade. During follow-up, 77 students (8.5%) experienced visual acuity decline. Large social jet lag, observed in 28.9% of participants, was independently associated with an increased risk of visual acuity decline (adjusted RR = 1.77, 95% CI: 1.13-2.78). These findings suggest that social jet lag is associated with visual acuity decline in junior high school students and may represent a relevant lifestyle-related factor in adolescent visual health.