A study was conducted to investigate the effects of intermittent illumination on stereopsis. Intermittency rates of 8Hz and 15Hz with pulse to cycle fractions of 1/4 and 3/4, plus steady, were utilized. A sphere-ring target with a forced choice judgment of the sphere being either before or behind the ring was intermittency being either binocular, or monocular to the dominant eye.Results from four observers indicate that the monocular intermittent condition provided the expected decrement in the 8–10Hz range that previously yielded impoverishment of visual acuity and unique changes in brightness, hue and saturation. The binocular intermittent condition also impaired stereopsis, however not in the 8–10Hz range. It was concluded that present ideas relating acuity and stereopsis are in need of revision.