Myopia and hyperopia are associated with opposite chronotypes in a sample of 71,016 individuals

Myopia, projected to affect half of the global population by 2050, is a growing healthcare concern. Chronotype, an output of the human biological clock, and sleep parameters have been associated with several diseases, including myopia. We explored the connection between refractive errors and sleep and circadian rhythm parameters by employing a sample of 71,016 adults who completed the Munich Chronotype Questionnaire in the Estonian Biobank. After accounting for possible confounders, such as age, sex, education level, and duration of daylight exposure, we observed that individuals with late chronotype, characterised by a delayed sleep-wake pattern on free days, had higher odds for myopia. In contrast, early chronotype was associated with hyperopia. Furthermore, increased social jet lag and reduced sleep duration were associated with both myopia and hyperopia. These results emphasise the complex interplay between circadian rhythms and sleep in refractive development, with potential implications for public health and clinical practice.