I would get migraines which lasted anywhere from a day to three days. It took me a long time to realize they were migraines, even though I had the ocular strobing/aura, could feel them coming a day in advance, etc. This went on for about fifteen years. Eventually I realized that they correlated to how much processed carbs I was taking in. I modified my diet, and the migraines ceased. Or so I thought. My headaches stopped, and the ocular migraine mostly stopped - although I would occasionally have them during and after exercise -- but it turns out that we can have migraine activity without having migraine headache.

Last summer I was driving on the highway, and out of the blue I lost vision in both eyes and started to black out. Happened within the space of a few seconds, then cleared. A few minutes later it happened again. Felt like a stroke. Went to the doctor and he put me on a very comprehensive (and expensive) battery of tests to rule out stroke, tumor, etc etc. Ultimately they decided it was cerebral arterial spasm / basal artery migraine. These can be dangerous (i.e. if you happen to be racing -- yikes!) but obviously better than the more scary alternatives.

If both eyes were affected, you might google basal artery migraine as a start. Migraine is a complicated thing and presents differently in different people & different times. Might be worth making a real effort to identify what triggers it for you. Mine were becoming somewhat debilitating, and I kind of lucked into realizing how to avoid or at least mitigate them. I would certainly recommend seeing a doctor to rule out the other worse stuff.