Research Progress on Ophthalmic Changes in Astronauts Induced by a Microgravity Environment and the Related Mechanism

A series of ophthalmic changes can occur after astronauts enter the microgravity environment. If these changes are not intervened or treated in a timely manner, it will cause long-term or permanent visual impairment to astronauts, which will not only affect the execution of flight missions, but also threaten the personal safety of astronauts. Although the precise mechanism of these ophthalmic changes in astronauts is still unclear, related studies have found that when astronauts enter the microgravity environment, there is intracranial pressure elevation, nervous system changes, biochemical changes, and lymphoid and venous circulation disorders, which may be involved in the occurrence and development of the disease. This paper summarizes these ophthalmic changes over a period of the last 50 years at home and abroad and their possible mechanisms after astronauts enter the microgravity environment. We want to identify the preventive and treatment measures for these ophthalmic changes, and provide relevant theoretical support for the screening and training of astronauts. Key words: microgravity; simulated microgravity; astronaut; visual impairment; space flight-associated neuro-ocular syndrome