Binocular convergence in man during total sleep deprivation

Abstract

It was proposed that binocular convergence (lateral phoria) for near and far vision would reflect the states of visual functioning and that there would be a progressive reduction in phoria during sleep deprivation. Six young male subjects underwent two conditions of sleep deprivation on separate occasions. One condition incorporated a high visual load and the other a low load. Exercise and sound were balanced. Lateral phoria for near and far vision was carefully measured, regularly, before, during and after sleep deprivation. It was found that a reduction in convergence (exophoria) for both near and far vision became increasingly apparent with progressive sleep deprivation, especially with near vision and under high visual load. The near vision measure, which included accommodation convergence, appeared to be more sensitive to sleep deprivation generally, whereas far vision tended to produce a greater differentiation between the conditions. The implications of these findings for REM sleep and oculomotor innervation are discussed.