EYE PROBLEMS IDENTIFIED ASSOCIATED WITH PROLONGED SPACE TRAVEL
NASA-backed institute calls on ophthalmic companies for space research on effects of prolonged weightlessness on vision
NASA has struggled to understand why astronauts returning from space missions are experiencing moderate to marked eye problems and changes in their vision. In an effort to prevent and combat these issues the National Space Biomedical Research Institute and the center for space medicine at Baylor University College of Medicine have launched the vision for Mars Challenge to help identify and advance medical technologies in ocular health in space.
Following the advent of the space station, it has been observed and demonstrated that exposure to weightlessness may have deleterious effects on human health. Astronauts on board the international space station battle nausea, vertigo, headaches bone loss and muscle atrophy. Vision changes have also been documented in NASA surveys of over 300 astronauts post prolonged missions of over 6 months revealed that over half of astronauts on orbital missions dating back to 1989 have complained about changes in near and distance vision, one of four on missions of less than 6 months also reported eye problems.
Older crew members, aged 40 and over, seem to be more predisposed to these changes that appear around six weeks of weightlessness and go on for months even after returning to earth. NASA is aware and has been dispensing reading glasses to all astronauts in anticipation.
In a recent study of 7 astronauts age 50 or older, 5 of 7 showed evidence of pathological processes undercutting their vision after their missions were complete. Abnormalities noted have included flattening of the posterior globe with associated choroidal folds and fluid accumulation around the optic nerve. It is theorized that these anatomical changes may be due to the effects of increased intracranial pressure during prolonged weightlessness.
These findings are impacting plans for long duration manned voyages such as an anticipated Mars mission. Development of rotational systems to generate artificial gravity will be required to address the concerns associated with these findings.