DETERMINATION OF ACHROMATIC VISUAL THRESHOLDS IN MAN FOLLOWING EXPOSURE TO ULTRASHORT, ULTRAVIOLET AND ROENTGEN WAVES.
SCHOOL OF AEROSPACE MEDICINE BROOKS AFB TEX
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A series of experiments was carried out using short electromagnetic waves, exposing wrists to small amounts of x-rays 30-100 r. It is known that erythema usually appears on the sixth day after a dose of 600 r. However, changes in the visual threshold were noted one day after exposure to doses that were 6 to 20 times smaller 100-30 r than the dose causing erythema. These changes were observed for several days. During the blind tests all conditions were the same with one exception a thick lead shield was placed between the patient and the source of radiation. In this manner, x-ray wave lengths from 1 x 10 to the minus 7th power to 1 x 10 to the minus 8th power cm millimicrons and tenths of millimicrons have, in either case, an effect on the autonomic nervous system. The experiments were continued using long electromagnetic waves rather than those of the visible spectrum. The experiment consisted of 47 tests on seven subjects. Control experiments heat applied on abdomen and back showed no changes. Ultrashort waves showed a marked effect on the visual threshold within a few hours. Separate tests were carried out also with short waves length of waves approximately 50 meters with equally valuable results. The experiments indicate that the autonomic nervous system of man is effected by a very large spread of electromagnetic wave lengths.