Effects of Extended Hypoxia on Night Vision

Abstract

The effects of sixteen days of sustained hypoxia (4300m equivalent) on the dark adaptation threshold function were studied. Twelve male subjects were measured periodically (days 2,4,6,9,11,13,16 of exposure) over a 20-min test period for both red and green stimuli using a new computerized dark adaptometer. Comparison with sea level performance showed negligible elevations of thresholds for red response, but highly significant impairment of green response (P<00001) over almost the entire dark adaptation function. These losses peaked between the sixth and ninth day followed by little recovery, except at the eleventh day when the subjects descended briefly to 3200m elevation. Impairments developed rapidly again upon return to the original higher altitude. The results differ from previous published findings based on shorted exposure periods which showed only slight impairments of the early segment of dark adaptation. Implications of the results are discussed.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1983
Accession Number
ADA129719

Entities

People

  • Calvin E. Witt
  • Harry Zwick
  • James A. Devine
  • John L. Kobrick

Organizations

  • United States Army Research Institute of Environmental Medicine

Tags

Communities of Interest

  • Biomedical

DTIC Thesaurus Topics

  • Altitude
  • Analysis Of Variance
  • Carbon Monoxide
  • Dielectric Gases
  • Elevation
  • Geographic Distribution
  • High Altitude
  • Light Sources
  • Military Operations
  • Military Research
  • Night Vision
  • Oxygen
  • Peak Power
  • Pulse Modulation
  • Recovery
  • Sea Level
  • Sensitivity

Fields of Study

  • Psychology

Readers

  • Circadian Sleep-Wake Regulation and Chronobiology
  • Mathematics or Statistics