Flattened eye of the astronaut.
Without gravity pulling down on fluids in their bodies, astronauts' faces get puffy and congested. This Charlie Brown effect---so named for the cartoonishly round faces---may be responsible for amusing anecdotes like hot sauce cravings
among astronauts, but it could also pose a permanent problem for their eyes. In a new study
, MRIs revealed swelling or flattening of eyeballs in an unusually high proportion---11 out of 27---of astronauts examined. The abnormalities matched what doctors see in Earth-bound patients with idiopathic intracranial hypertension
, or high pressure of fluids in the brain, which could be similar to what's happening in zero gravity. The study's authors are careful to note that they can't rule out other causes, such as exposure to radiation, and that they did not look at astronauts who had never been in space for comparison. Nevertheless vision problems are a known hazard
of space travel, and NASA is now scanning all eyeballs before astronauts leave for space. [via NYT
]
Image courtesy of Kramer et al / Radiology