According to the Baylor College of Medicine's Center for Space Medicine, long durations in space can change a person's eyes, including globe flattening, optic disc edema, and vision changes. The Space-Associate Neuro-ocular Syndrome (SANS) is a recognized condition which causes swelling in the back of the eye after a duration in space.

Butch Wilmore and Sunita Williams have been stuck in space after their originally scheduled eight-day mission ended up with a malfunction during takeoff.