Abstract
AIM: To determine the presence of symptomatic accommodative and non-strabismic binocular dysfunctions (A(NS)BD) in a non-presbyopic population of video display unit (VDU) users with flat-panel displays. METHODS: One hundred and one VDU users, aged between 20 to 34y, initially participated in the study. This study excluded contact-lens wearers and subjects who had undergone refractive surgery or had any systemic or ocular disease. First, subjects were asked about the type and nature of eye symptoms they experienced during VDU use. Then, a thorough eye examination excluded those subjects with a significant uncorrected refractive error or other problem, such as ocular motility disorders, vertical deviation, strabismus and eye diseases. Finally, the remaining participants underwent an exhaustive assessment of their accommodative and binocular vision status. RESULTS: Eighty-nine VDU users (46 females and 43 males) were included in this study. They used flat-panel displays for an average of 5±1.9h a day. Twenty subjects presented A(NS)BD (22.5%). Convergence excess was the most frequent non-strabismic binocular dysfunction (9 subjects), followed by fusional vergence dysfunction (3 subjects) and convergence insufficiency (2 subjects). Within the accommodative dysfunctions, accommodative excess was the most common (4 subjects), followed by accommodative insufficiency (2 subjects). Moderate to severe eye symptoms were found in 13 subjects with A(NS)BD. CONCLUSION: Significant eye symptoms in VDU users with accommodative and/or non-strabismic binocular dysfunctions often occur and should not be underestimated; therefore, an appropriate evaluation of accommodative and binocular vision status is more important for this population.