Visual Acuity In Relation To Body Orientation And G-Vector
Report Number: MRL TDR 62-74
Author(s): Pigg, Leroy D., Kama, William N.
Corporate Author(s): Aerospace Medical Research Labs Wright-Patterson AFB Ohio
Laboratory: Behavioral Sciences Laboratory
Date of Publication: 1962-07
Pages: 18
Contract: Laboratory Research - No Contract
DoD Project: 7184
DoD Task: 718406
Identifier: AD0285552
Abstract:
The Armed Forces Vision Tester, fitted with checkerboard targets, was used in tests of visual acuity under viewing conditions involving various combinations of gravity effects. Twenty-four subjects were tested for left, right, and binocular acuity of near and far vision in each of four body positions: standing upright, prone, supine, and inverted upright. The latter condition effectively produced -1 G acceleration. Intercomparisons of scores from these positions form the basis for useful generalizations concerning the effects on visual acuity of various acceleration environments, including 0 G. By comparison with their acuity at 1 G, subjects experience a decrement at -1 G of approximately 15%. This is comparable to the decrement found by other investigators at 3 G's. Since both -1 G and 3 G's are 2 G-units removed from 1 G, it appears that equal changes in either direction from the normal acceleration environment produce equal losses in visual acuity as a function of the amount of change. This conclusion is supported by results of a previous study of acuity at 0 G, in which a small but statistically significant decrement comparable to that at 2 G's was found.
Provenance: Lockheed Martin Missiles & Fire Control
Author(s): Pigg, Leroy D., Kama, William N.
Corporate Author(s): Aerospace Medical Research Labs Wright-Patterson AFB Ohio
Laboratory: Behavioral Sciences Laboratory
Date of Publication: 1962-07
Pages: 18
Contract: Laboratory Research - No Contract
DoD Project: 7184
DoD Task: 718406
Identifier: AD0285552
Abstract:
The Armed Forces Vision Tester, fitted with checkerboard targets, was used in tests of visual acuity under viewing conditions involving various combinations of gravity effects. Twenty-four subjects were tested for left, right, and binocular acuity of near and far vision in each of four body positions: standing upright, prone, supine, and inverted upright. The latter condition effectively produced -1 G acceleration. Intercomparisons of scores from these positions form the basis for useful generalizations concerning the effects on visual acuity of various acceleration environments, including 0 G. By comparison with their acuity at 1 G, subjects experience a decrement at -1 G of approximately 15%. This is comparable to the decrement found by other investigators at 3 G's. Since both -1 G and 3 G's are 2 G-units removed from 1 G, it appears that equal changes in either direction from the normal acceleration environment produce equal losses in visual acuity as a function of the amount of change. This conclusion is supported by results of a previous study of acuity at 0 G, in which a small but statistically significant decrement comparable to that at 2 G's was found.
Provenance: Lockheed Martin Missiles & Fire Control