My doctors continue to tell me that they are not sure that my decades of visual migraines were/are directly related to decades of high platelet counts. (Both problems "began" somewhere in my late 20's and only now in mid 60's was I tested and diagnosed with first ET, and then immediately after PV.) I get cluster migraines that come on and off for a few days, then maybe also the next week or two, then none for many months. I have gotten blind spots in my vision, rotating shimmers, and in one or two scary cases, a sensation like theater curtains quickly closing and reopening in my vision. The last was when my platelets were at their highest over a million, and I was struggling with treatment choices--I do believe that was a brain/eye pressure thing, not random tension. Like nohrt4me, I can usually avoid big headaches with tylenol or just deep breathing/relaxing, but neck pain and nausea and extreme tiredness can follow eye episodes. I'm on Besremi and it (or fate) is now quickly bringing hematocrit and platelets down, even at just over half dose at this point.