Part 3/6:
SANS primarily results from the effects of microgravity on the human body. In the absence of gravitational pull, bodily fluids redistribute, causing increased pressure on the optic nerve and altering the shape of the eyes. The symptoms are concerning and include swelling of the optic nerve, flattening of the retina, and difficulty focusing on objects.
Most of these ocular changes appear to reverse upon returning to Earth, but the long-term effects of extended stays in space remain poorly understood. This knowledge gap presents a formidable challenge for future exploratory missions, particularly those planned for Mars, where strategies must be developed to prevent permanent damage to astronaut vision.