Microgravity and Vision Impairments in Astronauts : Springer : 9783319178691 : 3319178695 : 25 Sep 2015 : Recent missions on board the International Space Station have revealed previously unreported physiological consequences of long duration space flight, particularly in eyesight, and in this Brief Dr. Seedhouse reviews the existing theories on what causes this degeneration and how long it will last. Notably, 60% of long-duration crews have reported subjective degradation in vision, a clear indication that further study is necessary before astronauts embark on even longer-term space missions. Decreased near-visual acuity was reported in 46% of ISS/Mir crewmembers, resulting in a change of up to 2 dioptres in their refractive correction. It is possible that ophthalmic changes have been present since the first days of spaceflight, but had been attributed to other causes; this approach to the issue as well as other hypotheses are all presented in full to give a broad foundation of the ex