Association of sleep timings, duration, consistency, and chronotype with premyopia and myopia among Indian children

Background To explore the association of sleep timings, duration, consistency, and chronotype with premyopia and myopia among Indian children. Methods This hospital-based cross-sectional study included 453 children, aged 6–12 years. Two myopia participants were selected for each individual with the corresponding premyopia or emmetropia. All children underwent cycloplegic autorefraction and ocular biometric tests. The Children's Sleep Habits Questionnaire (CSHQ) and parental information on behavioral habits were used to assess the association of sleep parameters with myopia and premyopia using logistic regression models. Results Both myopia and premyopia exhibited significant late bedtime, short sleep duration, early wakeup time on only weekdays, and longer weekend catch-up sleep than emmetropia children (p < 0.05). In multivariate analysis, late bedtime (more than 24:00 a.m.) on weekdays (Odds ratio, OR = 3.63, 95% CI [0.74, 8.68]) as well as on free days (OR = 1.04, 95% CI [0.02, 8.08]); and early wake-up time only on weekdays (5:00–6:00 a.m., OR = 2.16, 95% CI [0.24, 6.76] and 06:00–07:00 a.m., OR = 2.42, 95% CI [0.51, 8.44]) were associated with increased risk of myopia (all p < 0.05) but not premyopia. After adjusting the confounding factors, when each of the eight CSHQ subscale components was analyzed, only bedtime resistance, night waking, and daytime sleepiness scores were significantly associated with a higher risk for premyopia and myopia (p < 0.05). Conclusions The sleep quality components, including bedtime resistance, night waking, and daytime sleepiness, equally involve a higher risk for myopia as well as premyopia.