Health Implications in the Post-Space Shuttle Era
Changes in visual acuity seem to be directly related to microgravity exposure and duration of space flight missions. With the reduction in access to and from low earth orbit for US astronauts owing to the retirement of the Space Shuttle in 2011, most US missions to the International Space Station now extend between 3 and 6 months (as they are reliant on the Russian Space Agency for flight access), resulting in longer exposures to microgravity and, therefore, increased risk for the ocular findings described in this article.
These findings may have implications that lead to modification of flight strategy, such as shorter mission length and a decrease in the number of repeat missions (with a resulting loss in flight experience for crew members). Moreover, exploration class missions -- such as a mission to Mars, which may last up to 3 years -- may entail additional considerations for crew health (including vision) and safety.
The solution to mitigating these issues has been under investigation at NASA for several years. The answer probably lies in a combined engineering and preventive medicine approach to produce a joint vehicle-based and medical-based reduction in risk.
Medscape Family Medicine © 2012 WebMD, LLC
Cite this: Eleanor A. O'Rangers, Kieran T. Smart. Ocular Changes After Space Travel - Medscape - May 23, 2012.