In the present study, we examined the visual accommodation of subjects who were gazing fixedly at 3D images from two different displays: a cathode ray tube (CRT) while wearing special glasses and a liquid crystal display (LCD) while not wearing special glasses. The subjects were 3 people aged 20 years (2 people) and 36 years, all with normal vision. Visual function was tested using a custom-made apparatus (Nidek AR-1100). The instrument objectively measured
visual accommodative changes of the right eye in both binocular and natural viewing conditions. The target shown to subjects moved away slowly and disappeared at a distance about 3 m from the eye. The results suggested that it was easy and comfortable to focus on both the LCD and CRT. When the subjects viewed the progressively receding target, their accommodation was about 0.8 D at the presumed furthest points, a level at which the ciliary muscle is relaxed. The accommodative power differed by about 1.5 D from the near to far point. Thus, the ciliary muscle is repeatedly strained and relaxed while the subject views the moving target. In the present study, the subjects’ accommodative amplitude was changed when the target moved from the near to far point.
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