I have had ocular migraines for many years. The first diagnosis was when I had a retinal angiogram... (I had a blind spot from a airplane trip)...the doctor said it was a ocular migraine.

I don't get headaches very often. I've only had one migraine and that was when I was pregnant over 30 yrs ago.

But I still get ocular migraines--with the visual auras. They tend to come if I use Zantac. So I avoid that drug. I don't get them from cimetidine (which is also an H2 blocker). So that is rather a mystery. Mine typically start as a spiral in the center of my vision, of a diamond shaped design, which grows wider and wider , and eventually leaves my central vision and disappears.

I've only had 4 or 5 of the auras during my whole lifetime though so I don't consider it a common event.

Anyone with visual snow or disturbances in circulation should be taking B12 and folate to support the blood vessels in the retina.
Getting a homocysteine blood test may show elevations which damage the tiny vessels in the retina and brain. Often blood vessel damage shows up first in the eye.