FAA Office of Aerospace Medicine
Civil Aerospace Medical Institute

Report No: DOT/FAA/AM-13/20

Title and Subtitle: Hypoxia, Color Vision Deficiencies, and Blood Oxygen Saturation

Report Date: November 2013

Authors: Hovis JK, Milburn NJ, Nesthus TE

Abstract: Chromatic thresholds were measured using the Cambridge Color Test (CCT), Color Assessment and Diagnosis (CAD) test, and Cone Specific Contrast Test at ground and 3780 m (12,400 ft) for subjects with normal color vision and red-green color vision defects. The CAD revealed a small (~10%) increase in the red-green thresholds for the trichromatic subjects and a similar increase in the blue-yellow thresholds for the dichromats.

The other two color vision tests did not reveal any significant change in chromatic thresholds. The CAD results for the trichromats were consistent with a rotation of the discrimination ellipse counterclockwise, with little change in the elliptical area. This alteration in the color discrimination ellipse is consistent with the hypothesis that the effects of mild hypoxia on basic visual function are similar to lowering the retinal illuminance.

Key Words: Color Vision Deficiency, Color Vision, Hypoxia, Color Vision Screening Tests, Altitude

No. of Pages: 13