Why 70% of Astronauts Go Blind—Space Vision Crisis!

On long missions aboard the ISS, around 70% of astronauts develop Spaceflight‑Associated Neuro‑Ocular Syndrome (SANS)—a condition caused by fluid shifts in microgravity that can flatten eyeballs, inflate the optic nerve, and blur vision, sometimes permanently.

🔍 **In this video, you’ll learn:**

1. What exactly SANS is—and why NASA calls it one of the biggest health threats to Mars missions.

2. Biomechanical impacts: up to 33% drop in ocular rigidity, 11% lower intraocular pressure, and 25% reduced ocular pulse amplitude. (UdeM study)

3. Real astronaut experiences: clear vision becoming blurry in months, with symptoms persisting even after returning to Earth. (ScienceAlert, updated article)

4. NASA’s investigation & countermeasures: helmets, thigh‑cuff suits, rotational devices, and dietary or medication strategies to manage fluid balance.

🚀 For the future of human missions to Mars, understanding and preventing SANS is mission-critical.

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#AstronautHealth #VisionLoss #SANS #SpaceMedicine #NASA #MarsMission #Microgravity #ScienceAlert