Strobe Lights and Disappearing Faces...What Is "It"?

I was standing at the checkout line today at Costco, and the cashier's face disappeared, flashes of light appeared all around me, and then words on the walls were gone.  I knew what was happening, so no panic set in this time, but it took me back to the first time my vision started disappearing...
It was May 15th of last year, and our plane had just touched down on the island of Haiti.  I stepped off the plane to the overwhelming humidity and airport chaos coupled with already being sick. I looked at one of my teammates and I could only see half of her face.  I was in a foreign land and now my vision was gone.  It was as if strobe lights had been turned on in my brain and a party was started, but I wasn't invited, nor did I want to be invited.  Panic.  Fear.  A desire to turn around and hop on the next flight going back to Miami.  "It", for I knew not what "it" was called at this point, lasted 30 minutes.  "It" felt like an eternity, especially as thoughts swam through the current of my mind without knowing what was going on or how long "it" would last.  
About a month later another one showed up, followed by a couple more, and then a friend sent me some pictures of what it looks like to have an ocular migraine.  Aha, that's it, I thought.  I researched, pursued advice from health practitioners, and all of my symptoms lined up.  The "it" was ocular migraines.  Sometimes when you can identify the unknown, fear subsides and peace can restore its rightful place in our minds. 
It had been since July 10th, exactly 11 months ago, when I had last experienced this crazy thing my brain (and as I've been comforted to learn many others too) does.  So when today happened, there was frustration, but no panic and there was no fear.  I finished checking out, walked to the car, loaded up my belongings, and laid my seat back for 30 minutes until "it" passed.  
However, it's in these moments when you realize how fragile life is and how amazingly we've been created.  You have no choice but to slow down, and in a crazy, unpredictable way I become grateful for the thing that had at one point scared me to the core.