I don't know if this will help others as well as it has me . I found this easy solution after years of pain and desperation. I saw numerous Doctors and endured so many test and got no answers. I did the shots, I did the pills and I did the diets , Still got the headaches with loss/blurred vision. One day I was convinced my problem was digestive related . Just made sense . When I felt a session coming on I took a handful of tums. OMG it went away. What a break through. I figured out that the CALCIUM in TUMS was the reason for my almost instant relief. About 10 to 15 minutes. I now take four 600 mg of CALCIUM supplement when I start getting blurred vision. GONE IN 10-15 minutes. You can get these in any Walmart ( Spring Valley is in Walmart) or pharmacy . Very inexpensive. I truly hope this helps even one person . I know your pain and suffering. Please just try it.