VISUAL PERFORMANCE DURING WHOLE-BODY VIBRATION,

Abstract : Eight male volunteers were tested in the Boeing vibration facility to determine the effect of whole body vibration on the ability to read counter information. Stimuli consisted of five 5-digit counters varying in height from .05 to 0.2 inches (6 to 24 minutes visual angle at an average viewing distance of 28 inches). Vibration frequencies ranged from 1 to 27 cycles/second at each of four subjective reaction levels. Both vibration frequency and severity (reaction level) significantly affected two of the five counters. The size of the counter was a factor only if it subtended less than 12 minutes of arc. The most severe area of visual deterioration was from 12 through 23 cps. This was linked to the critical flicker frequency of the eye.