Operation Everest 2. Lack of an Effect of Extreme Altitude on Visual Contrast Sensitivity
Abstract
Contrast sensitivity thresholds were studied over 40 of during gradual ascent to a simulated terrestrial altitude of 25,000 ft in a decompression chamber. Only ambient pressure, and thus inspired oxygen pressure, was varied, thereby eliminating many of the confounding effects of cold, dehydration, malnutrition and exhaustion, inevitably encountered on very high mountains. Contrast sensitivity thresholds measured by the Ginsburg Vistech test showed no overall impairment as altitude increased. These results are different from those of other previously reported vision studies involving short exposures, lower altitudes, and lower test luminances. However, our results can be explained on the basis of the higher stimulus luminances used in our contrast sensitivity testing. Compared to the luminance levels involved in previously reported testing, our higher luminance stimuli would be less likely to be affected by hypoxia.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1988
- Accession Number
- ADA192673
Entities
People
- Allen Cymerman
- Barbara Shukitt
- Charles S. Houston
- Edith Crohn
- John L. Kobrick
- John R. Sutton
Organizations
- United States Army Research Institute of Environmental Medicine