Computer Vision Syndrome Prevalence and Ocular Sequelae among Medical Students: A University-Wide Study on a Marginalized Visual Security Issue

Mohammed Iqbal1, *
, Hosam Elzembely2, Ahmed Elmassry3, Mervat Elgharieb4, Ahmed Assaf5, Ola Ibrahim5, Ashraf Soliman5
1 Department of Ophthalmology, Faculty of Medicine, Sohag University, Sohag, Egypt
2 Department of Ophthalmology, Faculty of Medicine, Minia University, Minia, Egypt
3 Department of Ophthalmology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
4 Department of Ophthalmology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
5 Department of Ophthalmology, Faculty of Medicine, Ain Shams University, Cairo, Egypt

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© 2021 Iqbal et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: ( This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Department of Ophthalmology, Faculty of Medicine, Sohag University, Sohag, 82425, Egypt; Tel: +2 01068559840; Fax: +2 093 2159080; E-mail:



This study aimed to discover and document the potential of visual and ocular sequelae of computer vision syndrome (CVS) among medical students.


This cross-sectional case-control study was conducted on medical students (n=4030) of five universities in Egypt. All students completed a specially designed and validated CVS questionnaire survey (CVS-F3). Students with ≥5 CVS symptoms constituted a risk group (n=352), while students with 1-4 CVS symptoms constituted a low-symptoms group (n=3067). Students from the control and risk groups were examined using objective methods, such as visual acuity, subjective refraction, dry eye disease tests, and anterior segment and fundus examinations. Students who complained of visual blur underwent multifocal electroretinography mfERG examinations (mfERG group).


The CVS-F3 indicated that 84.8% of students had complaints that might be related to CVS, however, our ophthalmic examination group revealed only a 56% CVS prevalence rate. The most common single screen type used by 70.4% of students was the smartphone, and the most common complaint was headache (50.2%). Multivariate logistic regression analysis revealed that CVS was significantly associated with increased screen-hours, including >2 screen-hours daily (odds ratio [OR], 2.48; P<0.0001), >2 screen-hours at night (OR, 1.79; P=0.003), and ≥3 screen-years (OR, 1.69; P=0.006). In the mfERG group, 37% demonstrated reduced amplitudes of mfERG rings and quadrants, indicating reduced foveal responses.


CVS-questionnaires overestimate the true CVS prevalence and sequelae, which could be accurately detected by objective ophthalmic examination. Smartphones primarily caused CVS among students, with CVS severity increasing in correlation with shorter eye-to-screen distance and frequent use. Contact lens wearing doubled the risk of CVS development and augmented its severity. CVS might affect macular integrity with screen-induced foveal dysfunction.

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Keywords: Computer vision syndrome, Medical students, University students, Digital eye strain, Prevalence, Screens, Smartphone, Dry eye disease.