Prevalence of Computer Vision Syndrome and its Association with Sleep Quality among Undergraduate Medical Students: A Cross-Sectional Study

Abstract

Background: Computer vision syndrome (CVS), also referred to as digital eye strain, comprises a broad range of visual, ocular-surface, and extraocular symptoms associated with prolonged use of digital screens. Medical students may be particularly vulnerable because digital devices are integral to academic learning, communication, and leisure. Sleep is another potentially relevant dimension because evening exposure to light-emitting screens may influence circadian timing and sleep. Objectives: To determine the prevalence of CVS among undergraduate medical students, describe the distribution of visual, ocular-surface, and extraocular symptoms, assess awareness and screen exposure, and evaluate the association between CVS and sleep quality. Materials and Methods: A cross-sectional questionnaire-based study was conducted among 321 undergraduate medical students. CVS was operationally defined as the presence of at least one reported symptom in the visual, ocular-surface, or extraocular symptom domains in relation to digital screen use. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Descriptive statistics were used for participant characteristics and symptom profiles. The association between CVS and poor sleep quality (PSQI >5) was assessed using Pearson’s Chi-square test and odds ratios with 95% confidence intervals. PSQI scores between students with and without CVS were compared using the Mann–Whitney U test. Results: CVS was identified in 288 of 321 participants (89.7%). Visual complaints were reported by 237/321 (73.8%), ocular-surface complaints by 199/318 (62.6%), and extraocular complaints by 238/319 (74.6%). Most students (263/321, 81.9%) reported at least 2 h of daily screen exposure, whereas only 103 (32.1%) had previously heard of CVS. The mean self-rated knowledge score was 2.04/10. Complete PSQI scores could be derived for 274 participants; 132 (48.2%) had poor sleep quality. Poor sleep was significantly more frequent among students with CVS than among those without CVS (51.4% vs. 18.5%; χ² = 9.27, P = 0.002; odds ratio = 4.66, 95% confidence interval 1.71–12.69). The median PSQI score was also higher among students with CVS (6 vs. 3; U = 4990.5, P < 0.001). Conclusion: CVS was highly prevalent in this cohort, whereas awareness of the condition was low despite substantial daily screen exposure. Students with CVS had significantly poorer sleep quality than those without CVS. Incorporating digital eye-strain education, ergonomic measures, regular screen breaks, and sleep-hygiene counseling into undergraduate medical education may be beneficial.