[cryptonector]

For me it turned out to be sudden blood pressure drops.

I'd see my vision fade to yellow from the outside in. At 12 I had every damned test done by an ophthalmologist, only to come up empty. Much later, I had blood drawn for a test and when I stood after the same thing happened, but worse, and from everyone else's pov I fainted (I could hear and think, but not see or move). That's when I realized the issue was sudden blood pressure drops.

Sometimes this was accompanied by sugar lows, sometimes not.

Mind you, I never saw anything like the picture we're discussing here.