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Visual Acuity Changes in Shuttle Astronauts (LSAHNEWSV8_1)
Research Area:
Clinical medicine
Ocular physiological phenomena
Species Studied
Scientific Name: Homo sapiens Species: Human

Spaceflight experience and its resultant weightlessness cause various effects on the human body (e.g., facial fullness, bone density loss). The effect of microgravity on the eye and on visual acuity is a major focus of interest.

In normal vision (20/20), the cornea and the crystalline lens work together to focus the image on the fovea of the retina. This image is transformed into nerve impulses which are then transmitted by the optic nerve into the brain. Blurry vision results when refractive errors cause the light rays to not be focused on the retina. For example, the anomalous curvature of the cornea can cause myopia (nearsightedness), hyperopia (farsightedness),or astigmatism, whereas the loss of lens elasticity causes presbyopia (age-associated farsightedness).

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National Aeronautics and Space Administration. Visual acuity changes in Shuttle astronauts. In: Longitudinal Study of Astronaut Health Newsletter. February 1999;8(1):1.

Eye foreign bodies
Refraction, ocular
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Data Information
Data Availability
Archive is complete. All data sets are on the Web site.
Data Sets + View data.

Air quality
Dry eye
Eye accommodation
Eye irritation
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Mission/Study Information
Mission Launch/Start Date Landing/End Date Duration
LSAH 01/01/1989 05/31/2010 21 years

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)