This could be a freaky/fun thing to do as a VR demo.
Or one of the eye tracking kits.
My aura was similar to their description. I would be reading, and the words before or after the current one would be gone. I figured it was the migraine disrupting the visual processing parts of the brain so much so that the automatic filling in of the blind spot stopped working.
I realize there are people experiencing migraines and other painful experiences, but if you have occasional "I can't see right / my head hurts" experiences, consider seeing if drinking a lot more water helps. ;)
It's also related to that optical illusion with the cross and circle, where one seems to vanish when you stare at the other.
"migraine flash" might be "potential serious brain issue", I would pay close attention if you've got low/high blood pressures, abnormal blood, obese/anorexic.
Disclaimer: I'm not a medical professional, but I wouldn't play off something like this.
Unless brain damage was done, it's quite likely you can train yourself out of this habit by the way. One method I heard that works is to wear an elastic band, whenever you do it twang yourself on the wrist.
Often, key letters will just completely disappear. In their place is...a kind of grey blank that your mind jumps over. You could swear there's something there, and you can see it when you move your eyes quickly across the word, or out of the corner of your eye when you read the previous or next word, but it disappears when you steady your eyes on that word.