A study of visual comfort and visual fatigue at the point of accommodation response in viewing stereoscopic image

Abstract

Visual fatigue induced by viewing stereoscopic and planar HDTV images for about one hour at a viewing distance of 4.5m was evaluated. Scenes giving rise to particular visual discomfort were identified by continuous subjective evaluation, and the extent of the induced fatigue was estimated using both this and the difference in accommodation responses before and after viewing the test material. Results suggested that such scenes exercise spatio-temporal frequency limitations of binocular fusion mechanisms, which are more restrictive than comparable limitations for planar moving images. Moreover, even when the accommodation mechanism was judged to be operating open-loop, fatigue was clearly evident in the deterioration of the accommodation response. The results showed that in order to create visually comfortable stereoscopic images, it is necessary to consider not only the much-investigated conflict between vergence eye movement and accommodation, but also visual functions concerned with the processing of p arallax.