Forum for fellow migraine sufferers

Ggrandmother who has had visual migraines for 40 years! I have always had an aura, beginning as a tiny spot in my field of vision and expanding with flashing edges and moving out of my field of vision. A slight headache follows and some tiredness. Entire episode takes roughly and hour and would occur 4-5 times a year and even much less in recent years.
Yesterday I noticed I had a well defined circle of flashing light in the center of my vision, but was only affecting my left eye. At times I couldn’t see it but when outside or looking at a blank wall I could see it. It didn’t stay in my vision all the time but would flash when I would cut my eyes from side to side or if I held my head down when walking and it didn’t seem to change size at all. I went to my eye dr. and he said he believes it it is a ‘floater’ but I am really not sure. It does not float!! It seemed to get duller today and it almost gone tonight. So I am wondering if a visual migraine can last 24+ hours and if they can change their patterns over many years?

Thank you for any help you might offer..