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. 

The authors have declared no competing interest.

This research was supported by the European Union through Horizon 2020 research and innovation programme under grants no 810645 and 894987, through the European Regional Development Fund project no. MOBEC008, and the Estonian Research Council grants PRG1291 and PRG1414.

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The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

Estonian Committee on Bioethics and Human Research (Estonian Ministry of Social Affairs) gave ethical approval for this work (approval 1.1-12/624).

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Pseudonymised genotype and phenotype data are available from the Estonian Biobank (https://genomics.ut.ee/en/content/estonian-biobank) upon request.