Ocular Surface Alterations in Visual Display Terminal Users

Abstract
Background: Recent years have seen a dramatic increase in the amount of Work performed using Visual Display Ter-minals (VDTs) the extensive use of VDT has been accompanied by some adverse effects on the human health.
Aim of Study: To detect and evaluate ocular surface alterations among visual display terminal users.
Patients and Methods: This prospective observational study was conducted on three hundred VDT users who admin-istered a questionnaire which asked for the duration of using VDT per day, the type of VDT that often used, the position of VDT in relation to the eye and the distance between VDT and the eye, then 68 subjects of them consented to participate in clinical examination to detect any alterations in the ocular surface and the tear film.
Results: The duration of using VDT, the position of VDT in relation to the eye in addition to lighting used during VDT affects the ocular surface. As position of VDT above the eye level was conjoined with the increase in the severity of dry eye this may be because the increase in palpebral aperture and consequently increase the area for tear evaporation.
Conclusions: Using VDT associated with decrease in the blink rate and increase tear evaporation both of which can contribute to dry eye. Also using VDTs for long duration without breaks and positioning of VDT above the eye level both are accompanied by ocular surface alterations and dry eye.
Dim lighted environment and high brightness of VDT screen badly affects the health of the ocular surface and subsequently the functional visual acuity.