Computer vision syndrome (CVS) is a complex of symptoms experienced by up to 90% of computer users. Questions remain regarding its etiology. Changes in accommodation or vergence have been suggested as causative factors. This study sought to determine if subjects with CVS had abnormal accommodative or vergence facility findings and to identify if sustained computer use produces a change in these parameters. Twenty two subjects read text from a computer screen for a continuous 25 min period. Vergence facility and both monocular and binocular accommodative facility were measured. Following the computer task, subjects completed a questionnaire regarding their level of discomfort during the task. No significant change in monocular accommodative or vergence facility was observed following the computer task, although a small increase in post-task binocular accommodative facility was noted. The highest ocular symptoms reported were tired eyes, eyestrain and dry eye. These were not correlated significantly with the accommodative or vergence facility findings.The symptoms reported appeared to be related to dry eye, and not to either accommodative or vergence abnormalities.