Visual, ocular surface, and extraocular diagnostic criteria for determining the prevalence of computer vision syndrome: a cross-sectional smart-survey-based study

Abstract Background: The American Optometric Association defines computer vision syndrome (CVS), also known as digital eye strain, as “a group of eye- and vision-related problems that result from prolonged computer, tablet, e-reader and cell phone use”. We aimed to create a well-structured, valid, and reliable questionnaire to determine the prevalence of CVS, and to analyze the visual, ocular surface, and extraocular sequelae of CVS using a novel and smart self-assessment questionnaire. Methods: This multicenter, observational, cross-sectional, descriptive, survey-based, online study included ۶۸۵۳ complete online responses of medical students from ۱۵ universities. All participants responded to the updated, online, fourth version of the CVS questionnaire (CVS-F۴), which has high validity and reliability. CVS was diagnosed according to five basic diagnostic criteria (۵DC) derived from the CVS-F۴. Respondents who fulfilled the ۵DC were considered CVS cases. The ۵DC were then converted into a novel five-question self-assessment questionnaire designated as the CVS-Smart. Results: Of ۱۰۰۰۰ invited medical students, ۸۰۰۶ responded to the CVS-F۴ survey (۸۰% response rate), while ۶۸۵۳ of the ۸۰۰۶ respondents provided complete online responses (۸۵.۶% completion rate). The overall CVS prevalence was ۵۸.۷۸% (n = ۴۰۲۸) among the study respondents; CVS prevalence was higher among women (۶۵.۸۷%) than among men (۴۸.۰۶%). Within the CVS group, the most common visual, ocular surface, and extraocular complaints were eye strain, dry eye, and neck/shoulder/back pain in ۷۴.۵۰% (n = ۳۰۰۱), ۵۸.۲۷% (n = ۲۳۴۷), and ۸۰.۵۲% (n = ۳۲۴۴) of CVS cases, respectively. Notably, ۷۵.۹۲% (۳۰۵۸/۴۰۲۸) of CVS cases were involved in the Mandated Computer System Use Program. Multivariate logistic regression analysis revealed that the two most statistically significant diagnostic criteria of the ۵DC were greater than or equal to ۲ symptoms/attacks per month over the last ۱۲ months (odds ratio [OR] = ۲۰۴۱۷۷.۲; P <۰.۰۰۰۱) and symptoms/attacks associated with screen use (OR = ۱۶۰۴۷.۳۴; P <۰.۰۰۰۱). The CVS-Smart demonstrated a Cronbach’s alpha reliability coefficient of ۰.۸۶۰, Guttman split-half coefficient of ۰.۸۰۵, with perfect content and construct validity. A CVS-Smart score of ۷–۱۰ points indicated the presence of CVS. Conclusions: The visual, ocular surface, and extraocular diagnostic criteria for CVS constituted the basic components of CVS-Smart. CVS-Smart is a novel, valid, reliable, subjective instrument for determining CVS diagnosis and prevalence and may provide a tool for rapid periodic assessment and prognostication. Individuals with positive CVS-Smart results should consider modifying their lifestyles and screen styles and seeking the help of ophthalmologists and/or optometrists. Higher institutional authorities should consider revising the Mandated Computer System Use Program to avoid the long-term consequences of CVS among university students. Further research must compare CVS-Smart with other available metrics for CVS, such as the CVS questionnaire, to determine its test-retest reliability and to justify its widespread use.