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Near Vision Acuity and Contrast Sensitivity (DSO 408)
Research Area:
Clinical medicine
Ocular physiological phenomena
Species Studied
Scientific Name: Homo sapiens Species: Human

Both American and Soviet astronauts have reported conflicting experiences with visual capability in space. While some astronauts report considerable increases in visual capability, some report marked decreases in capability, and still others report no change. Since weightlessness causes disruption of the vestibular-ocular system and a redistribution of fluid throughout the body which could cause cerebral edema and changes in eyeball shape, changes in visual capability would not be unexpected. Studies using two different testing methods, near visual acuity and contrast sensitivity, were undertaken to determine the effects of weightlessness on vision. Near visual acuity was selected to determine changes in accommodation and other possible changes affecting vision. Contrast sensitivity testing was selected as a more precise measure of general vision loss as well as an aid in determining the possible physiological location and nature of vision changes. Evidence shows that significant losses in contrast sensitivity can occur with little or no effect on visual acuity.

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Visual acuity

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Data Information
Data Availability
Archive is complete. No data sets are available for this experiment. Please Contact LSDA if you know of available data for this investigation.

Visual acuity

Mission/Study Information
Mission Launch/Start Date Landing/End Date Duration
STS-41B 02/03/1984 02/11/1984 8 days
STS-41C 04/06/1984 04/13/1984 7 days
STS-41D 08/30/1984 09/05/1984 6 days
STS-41G 10/05/1984 10/13/1984 8 days
STS-5 11/11/1982 11/16/1982 5 days
STS-51C 01/24/1985 01/27/1985 3 days
STS-6 04/04/1983 04/09/1983 5 days
STS-7 06/18/1983 06/24/1983 6 days
STS-8 08/30/1983 09/05/1983 6 days

Additional Information
Managing NASA Center
Johnson Space Center (JSC)
Responsible NASA Representative
Johnson Space Center LSDA Office
Project Manager: Jessica Keune
Institutional Support
National Aeronautics and Space Administration (NASA)
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