My daughter had the same problems.  She would get blurry vision in her left eye and sometimes would lose vision for a little while.  Her vision episodes would come and go and last about 30 minutes or so when then happened.  She no longer has this issue since her carotid surgery in her neck.  My daughter also had blockage internal carotid arteries in the front of her neck which is unusual.  She ended up having a carotid endarterectomy on her right side.  The left side is also blocked but the arteries are too small to fix.  You may have them check your daughters carotids in her neck also. My daughter had carotid surgery in 2009 and moyamoya surgery in March 2010.

I have blurry vision as an adult in my mid 20s!!  I had surgery 6 years ago, but havent been able to get a check up in four years due to lack of insurance and finances.  Glad I'm not alone in this one. It sometimes takes me about 6 hours to wake up before the fog/migraine and blurry vision lifts.  I am korean, too. Adopted!  Are there doctors in Korea experienced with moyamoya? : )