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Vision and Aging in the Astronaut Population (LSAHNEWSV11_2_2)
Research Area:
Clinical medicine
Ocular physiological phenomena
Species Studied
Scientific Name: Homo sapiens Species: Human

Aging causes changes that may weaken your eyes, and affect your vision. Probably the most common aging effect of the eye is presbyopia, which affects more than 60 million Americans. This condition is caused by the loss of lens elasticity, resulting in the loss of the ability to focus on near objects or small print. Other aging-related conditions are less benign and can lead to irreversible blindness when left untreated. These diseases tend to begin painlessly and without symptoms in their earliest stages. Risk factors for these diseases include being over the age of 60, having a family history of the disease, or having the predisposing condition (e.g., diabetes). These eye diseases are described below.

Cataracts are cloudy areas or opacities in the lens, which may be caused by aging, or trauma. Cataracts, which form slowly and painlessly, may stay small and not interfere with vision. Fortunately, surgical treatment for advanced cataracts has a higher than 90% success rate. Cataracts affect almost 20.5 million people in the U.S. age 40 and older. The corresponding figures for the astronaut and comparison participants are 29 and 37, respectively.

Glaucoma is a buildup of pressure in the eye caused by an imbalance in fluid production and drainage. This increased pressure can damage the optic nerve, retina, or other parts of the eye. In some cases, elevated intraocular pressure is a clue to the condition, but in most instances glaucoma is only detected through a dilated eye examination. Glaucoma is controlled by medication, and surgery if necessary. More than 2.2 million people in the U.S. age 40 and older have glaucoma. Three astronauts and ten comparison participants age 40 and older have been diagnosed with glaucoma.

Retinal disorders: the two most relevant retinal disorders are age-related macular degeneration (AMD) and diabetic retinopathy. In AMD, vision deteriorates when the macular cells in the retina break down for reasons that are yet unknown. AMD rarely leads to complete blindness; however, it will lead to loss of central vision function, thereby potentially effecting one's ability to perform discriminating tasks such as reading, driving or watching television. Its effects can range from mild to profound. AMD cannot be cured, but it may be slowed by laser treatment, or medication and nutritional supplementation with antioxidants. Vision loss can be improved by low-vision aids. More than 1.6 million people in the U.S. age 50 and older have AMD. This condition affects one astronaut and five comparison participants age 50 and older.

In diabetic retinopathy, chronic high glucose levels lead to damage in retinal blood vessels. This condition is the most common vision complication that diabetics suffer, and is the leading cause of new blindness. Controlling the underlying disease, diabetes, is the best prevention. Diabetic retinopathy may be slowed or stopped through surgery, when it is diagnosed in its early stages. This disease affects more than 5.3 million people in the U.S. age 18 and older. No Longitudinal Study of Astronaut Health (LSAH) participant has reported being diagnosed with diabetic retinopathy.

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National Aeronautics and Space Administration. Surveillance of Health Risks Among Older Adults. In: Longitudinal Study of Astronaut Health Newsletter. January 2003;11(2):1.

Diabetic retinopathy
Macular Degeneration

Data Information
Data Availability
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Data Sets + View data.

Diabetic retinopathy
Macular degeneration

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)