AccScience Publishing / GPD / Online First / DOI: 10.36922/GPD025140030
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ORIGINAL RESEARCH ARTICLE

Educational attainment, screen time, body height, physical activity, sleep duration, and risk of astigmatism: A Mendelian randomization study

Chenglin Zhu1 ,  Hao Fan1 ,  Ningxuan Zhang1 ,  Haoyang Liu1 ,  Lei Zhang1 ,  Xinying Ji2,3* ,  Yalong Dang4,5*
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1 Henan International Joint Laboratory for Nuclear Protein Regulation, School of Basic Medical Sciences, Henan University, Kaifeng, Henan
2 Department of Nuclear Medicine, Henan International Joint Laboratory for Nuclear Protein Regulation, the First Affiliated Hospital, Henan University, Kaifeng, Henan, China
3 Department of Microbiology and Immunology, Henan Provincial Research Center of Engineering Technology for Nuclear Protein Medical Detection, Medical School of Health, Zhengzhou Health College, Zhengzhou, Henan, China
4 Department of Ophthalmology, Sanmenxia Eye Hospital/Sanmenxia Central Hospital, Sanmenxia, Henan, China
5 Henan International Joint Laboratory of Outflow Engineering, Sanmenxia Central Hospital, Sanmenxia, Henan, China
GPD, 025140030 https://doi.org/10.36922/GPD025140030
Received: 5 April 2025 | Revised: 6 February 2026 | Accepted: 9 February 2026 | Published online: 29 April 2026
© 2026 by the Author(s). This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution 4.0 International License ( https://creativecommons.org/licenses/by/4.0/ )
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Abstract

Astigmatism is a common refractive error with substantial visual and public health implications, yet its underlying causal determinants remain incompletely understood. To assess the independent causal effects of educational attainment, screen time, body height, sleep duration, and physical activity on astigmatism, we conducted a Mendelian randomization (MR) study. This analysis was based on a two-sample MR design using publicly available genome-wide association study summary data from individuals of European descent. Genetic variants significantly associated with each exposure at the genome-wide level were chosen as instrumental variables. Causal associations were primarily estimated using the inverse variance–weighted (IVW) method, while weighted median and MR-Egger approaches were applied to evaluate the robustness of the results. Heterogeneity and pleiotropy were assessed with Cochran’s Q, MR-Egger intercept, MR-PRESSO, and leave-one-out analyses. The findings from IVW indicated that higher educational attainment (odds ratio [OR] = 1.058; 95% confidence interval [CI] = 1.048–1.067; p = 1.91 × 10−32), longer screen time (OR = 1.028; 95% CI = 1.016–1.041; p = 3.19 × 10−6), and greater body height (OR = 1.004; 95% CI = 1.002–1.006; p = 4.00 × 10−4) were causally associated with increased astigmatism risk. No evidence supported causal effects for physical activity or sleep duration. Sensitivity analyses (weighted median, MR-Egger, MR-PRESSO, leave-one-out) yielded consistent results and did not indicate directional pleiotropy. Our MR study supports causal roles for educational attainment, screen time, and body height in astigmatism development among individuals of European ancestry. These findings highlight potential targets for early screening and motivate mechanistic studies to clarify biological pathways.

Keywords
Mendelian randomization
Astigmatism
Educational attainment
Screen time
Body height
Funding
This work was financed by the National Natural Science Foundation of China (No. 81870591), Key R&D and Promotion Projects in Henan Province (No. 242102310407), the Key Scientific Research Projects of Colleges and Universities in Henan Province (No. 23A310011), and the Henan Province Medical Science and Technology Research Program Project (No. LHGJ20230428).
Conflict of interest
Lei Zhang and Xinying Ji serve as an Editorial Board Member and an Associate Editor of this journal, respectively, but they were not in any way involved in the editorial and peer-review process conducted for this paper, directly or indirectly. Separately, other authors declared that they have no known competing financial interests or personal relationships that could have influenced the work reported in this paper.
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Gene & Protein in Disease, Electronic ISSN: 2811-003X Published by AccScience Publishing
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