When we shut our eyes at night up on space station, you can see what actually looks like a shooting star go by your eyes if you get hit by a piece of radiation. One theory is that these particles could be hitting astronauts' retinas and making their rods and cones fire which would lead them to see a flash of light that isn't really there. Some people experience a change in eyesight because you think about maybe there's a little more pressure on the back of your eyeballs. So instead of being shaped like almonds, they get to be a little more round. Bone density is a problem too. Because her spine wasn't constantly being compressed by gravity, the space between Ann's