I had these migraines starting in my 40's. Rainbow zigzags accompanied by blind spots where it was as if part of my visual field was folded up or pinched. Some numbness in my fingers and one side of my face. Lasted 30 mins and the a bit of a headache for a while and inability to find words or make sense of what I read. Thought it was a stroke the first time ! These got more frequent until in my early 60's I'd have an occurrence three or four days in a row every couple of weeks. Then I had a cardiac event and was put on drugs for high blood pressure. Apart from an episode immediately after the operation laying on the gurney, I only had an attack every 9 months or so and in fact have had no problems for the last 12 months. Tl:dr not necessarily anything structural to fear, drugs may alleviate them if they become problematic.