I don't know if this is what you mean, but many years ago, I had a passing episode of central vision blindness in my right eye - like a hole was punched in the center of my visual field. After a few minutes, it passed.
I was terrified, naturally, and saw an opthmalogist and then a cardiologist (to see if it had been a blood clot). The diagnosis was a migraine in the blood vessel feeding my ocular nerve. Happily the spasm stopped quickly enough that there was no permanent damage to my vision.
I don't know if this diagnosis was actually correct or if you are referring to something similar or not, but I thought I'd share my experience.
This happened to me in 1990, by the way, and never occurred again - though I get plenty of the usual type of migraines (too many).