could be from low magnesium, j. also, combined with the blurred vision, you might want to consider zinc. what's your diet and supplement regimen like, IIMA?
READ ME key info on nutrient targets - www.thisisms.com/ftopict-2489.html
my approach: no meds so far - just nutrient-dense anti-inflammatory whole foods, and supplements where needed
info: www.whfoods.com, www.nutritiondata.com