J Compr Ped. 2017 February; 8(1):e43208. Published online 2017 February 21. doi: 10.5812/compreped.43208. Research Article The Prevalence of Asthenopia and its Determinants Among Schoolchildren Hassan Hashemi, 1 Mehdi Khabazkhoob, 2,3 Samira Forouzesh, 4 Payam Nabovati, 3 Abbas Ali Yekta, 4,* and Hadi Ostadimoghaddam 5 1 Noor Research Center for Ophthalmic Epidemiology, Noor Eye Hospital, Tehran, Iran 2 Department of Medical Surgical Nursing, School of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences, Tehran, Iran 3 Noor Ophthalmology Research Center, Noor Eye Hospital, Tehran, Iran 4 Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran 5 Refractive Errors Research Center, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran * Corresponding author: Abbas Ali Yekta, Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran. E-mail: yektaa@mums.ac.ir Received 2016 October 19; Revised 2016 December 25; Accepted 2017 January 21. Abstract Objectives: The current study aimed at determining asthenopia prevalence and its associated factors in a population of high school students. Methods: In the current cross sectional study, samples were selected from high school students (range, 12 to 18 years) in Kermanshah city, Iran, through stratified cluster sampling. Any person with at least 1 symptom was considered to have asthenopia. Results: Of the 1070 selected samples, 1040 participated, and examinations were completed for 901 students. The prevalence of asthenopia was 49.4% (45.7 to 53.2). The prevalence of asthenopia was 62.8% (51.9 to 73.8) and 47.7% (43.8 to 51.7) in males and females, respectively (P = 0.013). Asthenopia prevalence increased from 21.4% in 12-year-old to 63.9% in 18-year-old cases (P < 0.001). The most common symptom in the study was tearing (20.03%) and eye pain (19.88%) during near-work and reading. Conclusions: The prevalence of asthenopia in this student population was high. Since asthenopia can interfere with near-work, its treatment merits high importance in school-age children. Keywords: Asthenopia, Cross Sectional Study, Schoolchildren, Middle-East 1. Background Asthenopia is a term used to describe a variety of non- specific symptoms associated with the visual system, espe- cially during nea-work (1). Asthenopia is examined subjec- tively. This subjective problem entails 2 groups of symp- toms; nonspecific symptoms including fatigue, burning, irritation, eye pain, aching eyes, sore eyes, and headache, and specific symptoms are defined as symptoms such as photophobia, blurred vision, double vision, itching, tear- ing, dryness feeling, and foreign body sensation (2). Previous studies indicate that asthenopia mostly oc- curs due to uncorrected refractive errors, (3) accommoda- tive dysfunctions (4, 5), vergence anomalies (6, 7), inap- propriate lighting condition (8), extraocular muscle im- balance (9), and compromised quality of the viewed image such as poor contrast (10). Thus, asthenopia is categorized accordingly as internal and external. Internal asthenopia is caused by problems such as uncorrected refractive er- rors and accommodation disorders, while insufficient am- bient lighting is responsible for external asthenopia (2). This eye problem interferes with near-work, especially in children and can interfere with attention and academic performance (11). Along with increased use of computer devices and other near-work in children, the prevalence of asthenopia and its associated complications are expected to increase (12). Nonetheless, authors‘ knowledge about the preva- lence of this subjective problem is limited to few stud- ies. Review of different studies in children show that the prevalence of asthenopia and certain symptoms range from below 15% to over 80%, and headaches are 1of the most common symptoms reported in most studies (13). Al- though many studies are conducted on computer opera- tors to show the prevalence of asthenopia, (1, 14) few re- ports are available regarding schoolchildren (11, 15). More- over, studying the causes of asthenopia can improve the ability to treat this condition and resolve symptoms in af- fected individuals. In Iran, some studies assessed vision problems in schoolchildren (16-18); however, asthenopia is not studied in any age group of Iranian students. The cur- rent study was conducted to examine the prevalence of as- thenopia and its related factors in a student population in Iran. Copyright © 2017, Iranian Society of Pediatrics. This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited.