Purpose: COVID-19 pandemic caused an increase in digital screen time, which seemed to increase the prevalence of dry eye symptoms among the population with abnormally high digital screen usage hours. However, there are no reports of dry eye symptoms in school children with high digital usage hours. Therefore, the present study aimed to assess the prevalence of dry eye symptoms and evaluate the associated factors among school children aged 12 to 18 years during the COVID-19 outbreak. Methods: Multistage cluster sampling was applied, and six sections of online questionnaires were distributed to selected respondents in November 2021. The odds ratio (OR) with confidence intervals (CIs) for the factors was calculated using binary logistic regression. All statistical significance was determined at p < 0.05. Results: The findings revealed that 62.5% of 603 students showed symptoms of dry eye (DEQ-5 score ≥ 6). Significant associated factors included being female (adjusted OR (aOR) 1.54; 95% CIs 1.05–2.25), higher-grade student (aOR 1.77; 95% CIs 1.23–2.57), digital screen time use (6 to < 12 hours: aOR 2.00; 95% CIs 1.12–3.57, ≥12 hours: aOR 2.54; 95% CIs 1.39–4.76), and perceived stress (aOR 1.12; 95% CIs 1.08–1.16). The Thai-Perceived Stress Scale-10 scores were positively correlated with the scores on the 5-item dry eye questionnaire (Spearman’s r = 0.38, p-value < 0.01). Conclusion: A high prevalence of dry eye symptoms might be common among school children during the COVID-19 outbreak. Significant risk factors include being female, being a higher-grade level student, prolonged use of digital screens, and perceived stress. However, contact lens use, smoking, and the most common digital device usage patterns were not found to be contributing factors.

Circadian regulation has emerged as an important modulator of ocular growth; however, its role in organizing retina–choroid transcriptomic responses during myopia development remains incompletely understood. In this study, we reanalyzed publicly available retinal and choroidal RNA-seq datasets from chick models of form-deprivation myopia using a multistage machine learning framework. A biologically motivated ZT8/12 circadian window was defined from prior published time-of-day transcriptomic evidence and evaluated using feature selection, cross-tissue and cross-stage validation, and external validation in an independent retinal dataset. Machine learning models classified the ZT8/12 window with high performance across onset and progression datasets, and control analyses indicated that this signal reflects a broad transcriptome-wide temporal state rather than a pattern unique to the 53-gene signature. The final gene signature is therefore interpreted as a stable representative subset of the ZT8/12-associated expression state. Cross-species functional enrichment and ortholog mapping suggested hypothesis-generating functional relationships between chicken genes and human orthologs. Overall, this work provides a computational framework for evaluating time-associated expression patterns in myopia and highlights circadian timing as a candidate component of retina–choroid biology requiring further functional validation.

Purpose To determine whether circadian timing defines critical molecular windows in myopia development and to assess the transferability of circadian gene programs across ocular tissues, disease stages, and species. Methods Publicly available retinal and choroidal RNA-seq datasets from chick models of form-deprivation myopia were analyzed using unsupervised transcriptomic profiling and multistage machine-learning classification. Circadian windows were defined based on Zeitgeber time, and samples were grouped accordingly for downstream analyses. Classification model robustness was evaluated through cross-tissue and cross-stage validation and further assessed using external validation in an independent dataset. Functional translation to humans was examined using ortholog-based Gene Ontology enrichment analysis to identify conserved biological processes and higher-order regulatory pathways. Results A circadian critical window at ZT8–ZT12 exhibited the strongest transcriptional divergence during both myopia onset and progression. Gene signatures derived from this window generalized across retina and choroid and remained predictive across disease stages, supporting coordinated molecular regulation between ocular tissues. External validation confirmed the reproducibility of these signatures despite differences in experimental design and gene coverage. Functional mapping revealed that conserved molecular components in chicks are reorganized into more complex neuroendocrine and regulatory networks in humans, indicating cross-species conservation with increased functional complexity. Conclusions Circadian timing strongly shapes myopia-related gene expression and underlies coordinated retina–choroid signaling. These findings highlight circadian biology as a key factor of refractive development and suggest that time-dependent mechanisms may influence myopia susceptibility, progression, and response to treatment.