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.
The purpose of the present study was to evaluate the effects of vision therapy in a school setting in which elementary school children, enrolled in a reading-mentoring program, Caring Adults Teaching Children How (CATCH), were trained as a group. The experimental goal was to improve visual-motor and visual perceptual skills, with the use of vision therapy in short sessions given weekly at school, to children with reading difficulties. Sixty students were selected after the use of the Developmental Eye Movement test's (DEM) exclusion criteria and were randomly assigned into one of two groups: vision therapy and non-therapy. Both groups received CATCH tutorial visits once a week for 50 minutes. In addition, the therapy group received a weekly 30 minute activity session in which three activities were completed from the following: oculomotor, accommodation, binocularity, visual motor and visual memory. The results revealed that vertical and horizontal eye movements and accommodative facility were significantly improved after 22 sessions of group vision therapy. These improvements were related to attentional mechanisms leading to improved reading abilities. We believe this preliminary study gives evidence of the advantages of a program whereby vision therapy is provided in the elementary school setting to advance deficient visual skills that are related to learning and cognitive enhancement.
The use of suppression control is essential in binocular accommodative facility testing. This study was designed to investigate accommodative facility performance comparing the use of Polarized material versus anaglyphic material (red-green). Both devices are commonly used to monitor for suppression in the clinical setting. Seventy-five subjects performed one-minute binocular accommodative facility tests with both anaglyphic and Polaroid systems. Statistical analysis showed a significantly higher result (1,933 cycles per minute) when the Polaroid filters were used. The results show the need for further study to develop independent sets of normed values when different methods of suppression control are utilized.
Accommodative facility, vergence facility and random dot stereopsis were evaluated in a sample of 43 university baseball and softball players. All had previously passed a modified clinical vision screening. Seventeen subjects were categorized with low accommodative or vergence facility, but only three were low in both. Three of the subjects, including one with low accommodative facility failed the Random Dot E test.
A sample of 228 children ranging in age from 6-13 years were administered tests using the computerized Wayne Saccadic Fixator. This study reports the standardized means and standard deviations of the following computerized procedures: near-far-near, visual preaction time and visual reaction time. The results of all procedures were compared by factors of age and sex. With normative data established for the computerized Wayne Saccadic Fixation procedures, the instrument can be more readily used to test specific visual functions.