Hi jeff,
Just to let you know you're not alone as I have very similar symptoms; starts of as a disturbance of vision just off centre, might just be like a few flickering pixels! and I know I'm in for an Aura!! Mine starts to get bigger into, quite often a C, of spectral flashing zigzag which gets bigger and bigger, leaving a blind spot in the middle of the C, which gradually moves to the peripheral of the visual field and disappears, this takes 20~30 minutes. No headaches, sometimes a muggy feeling for a few hours afterwards. I've had mine since I was 30, I'm now 64. Often related to fatigue and/or stress, but other times no obvious cause. I get about 10 or 12 a year, but not regular, can go several months without one then, out of blue I get one, like today!!, Last one was back in April, I've had 6 so far this year. Last year was x10, a few years ago it was x3. I keep a diary on the calendar. 46 in the past 8 years or 46 in 2920 days!! I've never found anything to suppress them, nor have I found any obvious triggers, I've kept a food diary, fluid diary, no triggers, I've tried various pressure point exercises I've read about and nothing shortens that 30 minutes!! When explaining to others what I experience I have found a few useful videos on you tube, I won't post direct links, but one is titled "Migraine Visual Aura" by the MAYO clinic, its not identical but its similar, there was a better one but I can no longer find it! perhaps I should have booked marked it"!! Anyway, i thought I'd just share with you my experiences.