A significant number of astronauts spending extended time aboard the International Space Station (ISS) have reported changes to their vision, raising concerns for future deep-space missions. Reports indicate that 70 percent of astronauts who have spent between six to twelve months in microgravity have experienced noticeable shifts in eyesight. Symptoms linked to spaceflight-associated neuro-ocular syndrome (SANS) include swelling of the optic nerve, flattening at the back of the eye, and vision impairment. The phenomenon is attributed to fluid redistribution in microgravity, which increases pressure on ocular structures. While many astronauts recover upon returning to Earth, the long-term impact remains uncertain, making it a critical issue for extended missions beyond low Earth orbit. Findings of the Study According to a study, Microgravity, researchers led by Santiago Costantino at the Université de Montréal examined 13 astronauts who had spent five to six months on the ISS. Participants from the United States, Europe, Japan and Canada, with an average age of 48, were included in the research. Eye measurements were taken before and after spaceflight, focusing on ocular …