Taiwan's high-tech industry occupies a pivotal position in the global market, and consequently, the proportion of people engaged in the high-tech industry is also remarkably high. The internet, computers, and other related electronic products are practically omnipresent in every corner of Taiwan [1–2]; however, research has indicated that the prolonged use of electronic devices can result in symptoms of discomfort, including eye soreness, redness, pain, dryness, burning sensation, and blurred vision [3, 4], which are collectively referred to as Computer Vision Syndrome (CVS).
From a clinical perspective, CVS appears to have a significant correlation with binocular vision [5–6], which is closely related to visual performance in daily life [7, 8]. Patients with binocular vision abnormalities typically show many ocular physiological and psychological responses in a clinical setting, such as blurred vision, headache, eye strain or discomfort, intermittent diplopia, inattention, eye rubbing, excessive blinking, and photophobia [9–14]. For example, minor esophoria and exophoria usually do not cause severe discomfort for patients in a clinical setting. However, when individuals engage in near reading, both eyes must move inward simultaneously. In a condition where equal convergence demands are met, individuals with a basic exophoric eye position require more effort to achieve a clear and stable visual effect [15]. The most common type of abnormal binocular vision is convergence insufficiency, which may be indicated by a basic exophoric eye position combined with a farther near point of convergence, poorer negative fusional vergence, or lower AC/A ratio [16–18] which also known as the relationship between accommodationa and convergence system. Patients with such conditions often complain of eye fatigue, blurred vision, and diplopia during reading or near work. Those with more severe symptoms or higher visual demands may even experience difficulty concentrating or headaches. The symptoms of binocular vision dysfunction above are very similar to CVS and dry eye [5–6]; thus, the mutual influence among CVS, dry eye, and binocular visual functions has also made the diagnostic process more complex in many clinical cases [19–20]. High-tech engineers may experience more severe dry eye and CVS symptoms due to prolonged and specific computer use. However, no research has demonstrated a relationship between dry eye and CVS. In high-tech industry professionals, specifically regarding binocular vision. This lack of evidence serves as the primary motivation for conducting this study.
The Computer Vision Symptom Scale questionnarie (CVSS-17) quantifies the visual performance of professionals who spend prolonged periods using computers [21–23]. This questionnaire analyzes the potential effects of prolonged computer use and classifies them based on the frequency and severity of various symptoms, thereby determining the overall severity of different symptoms. The participants in this study were all professionals in the high-tech industry who commonly use desktop or laptop computers for work during their working hours. Their computer usage time exceeded the average duration of 8–10 hours. The purpose of this study was to investigate the relationship between binocular visual function and visual symptoms in high-tech industry subjects.