Abstract
Purpose: :
The purpose of this study was to investigate whether there was any change in the accommodative functions after five hours of computer use in non-presbyopic adults. We also investigated whether there was any correlation between accommodative facility and ocular symptoms.
Methods: :
A sample of 34 subjects aged between 18-45 years working at DHL offices in southern part of Sweden was recruited. All the subjects had no ocular pathology and had normal visual acuity. The binocular amplitude of accommodation, monocular and binocular accommodative facility and accommodative response were measured in the morning, before they started their work, and repeated again after five hours of computer use. A questionnaire with questions related to eye-related symptoms at the end of the day was provided to all the subjects.
Results: :
A paired t-test showed a significant difference in mean binocular amplitude of accommodation between before and after five hours of computer use (p < 0.05). The mean binocular amplitude of accommodation before and after the computer use was 7.71 ± 2.09 D and 7.40 ± 2.01 D respectively and both the amplitudes were relatively normal for this sample’s mean age (33.4 ± 6.2 years). The mean accommodative facility with ± 2.00 D flippers was 6.4 ± 4.9 cpm in the right eye and 6.3 ± 5.1 cpm binocularly. A paired t-test showed a significant difference in the mean monocular and binocular accommodative facility before and after computer use (p < 0.05). The accommodative response before and after five hours of computer use was 0.15 ± 0.17 D and 0.20 ± 0.22 D respectively. There was no significant correlation between the eye-related symptoms score and accommodative facility (p > 0.05, r = 0.2). We also found no significant correlation between the symptom score and the computer screen distance at which the subjects were working or the amount of hours of computer use per day.
Conclusions: :
There was a small but statistically significant change in the accommodative functions after five hours of computer use in this sample of non-presbyopic adults. The mean binocular accommodative facility in this study was lower than the previously published data for adult population. We found no correlation between the symptom scores and the accommodative functions.
Keywords: accommodation • binocular vision/stereopsis • clinical (human) or epidemiologic studies: prevalence/incidence