Abstract
20 [male][male] who met the standards of the Service Air Corps were exposed in a low pressure chamber to a simulated altitude of 10,000 ft. for 5-6 hrs./day, 6 days/wk., for 4-6 wks. Before, during, and after the test, the peripheral vision of each subject was analyzed by a quantitative campimeter. During the 3d or 4th wk., 13 subjects developed a marked and progressive impairment of peripheral vision. The effect was only slowly reversible. 4 subjects tested at 11,500 to 18,000 ft. showed earlier visual symptomatology and even slower recovery.