Sometimes I cry or cough so hard I see white vein or lightning shaped flashes at the edge of my vision. (Especially if I'm in the dark) Why is that? Is that normal?
Answers (1)
Well, it's not exactly normal. You are shaking your head so hard that the nerves are mechanically stimulated. You can get a similar effect by pushing gently on the side of your eyeball. You see the light on the side opposite where you push. That is because your eye sees everything reversed.