I have these really bad headaches and while having them I see these blurry lines that start off by having one, then go to a lot. Then after about an hour they go away. How do I keep from having these, cause I never know when they're coming and I don't know when to take tylenol or anything ahead of time to not have them. Because when I have them it's hard to read things and I can't see good. -help!?!?!