Daytime Visual Acuity of Observers through a Window with and without Binoculars

摘要

Visual acuity with and without hand-held M-19 7x50 binoculars was tested inside and outside of the cab of a Master Surveillance Control Facility (MSCF) Tower. High, medium and low contrast 3-bar resolution test charts were used at a 400-foot distance. Except for low contrast bar patterns, where loss was not large, unaided eye visual acuity was not impaired by cab windows. With binoculars there was a statistically significant, though not large, window-caused loss of visual acuity for all contrasts. Even so, binocular visual acuity for high, medium and low contrast patterns was 5.6, 5.5, and 4.8 times, respectively, better than unaided eye acuity. Recommendations for the MSCF, based on this study, were made. A section of the report examines visual considerations in fence surveillance. (Author)