Contrast sensitivity and the effect of 60-hour sleep deprivation.

PURPOSE: The study aimed to evaluate the possible influence of prolonged sleep deprivation on achromatic and chromatic (red-green and blue-yellow) contrast sensitivity (CS). METHODS: During 60-hr sleep deprivation, CS was measured in 11 naval officers every sixth hour using videographic (Vigra-C) sine-wave-generated stimuli. RESULTS: When comparing the CS measurements obtained in the first and last 24 hr of the study, no statistically significant mean changes of achromatic CS (2.0, 5.9 and 11.8 cpd) or yellow-blue CS (0.6, 2.0 and 4.7 cpd) were found, while a significantly increased mean red-green CS at 2.0 and 4.7 cpd was recorded in the last 24 hr (p = 0.003 in both). The variance of achromatic and chromatic CS measurements in the group did not differ significantly in the first and last 24 hr test periods. CONCLUSIONS: Prolonged sleep deprivation does apparently not cause clinically or occupationally significant changes of contrast sensitivity in otherwise healthy subjects with normal visual acuity.