Blindness and migraine?

My 13 year old daughter has had a chronic migraine for about three years, and in the past few months has been going blind in both eyes about once a day. She says that her vision usually flickers before and after losing it completely, and the total blindness never lasts for longer than a minute. Her neurologist says that this is normal for migraine, but I have searched the internet and not found anything describing total blindness in both eyes caused by migraine. Should we get a second opinion?

[meikman]

I get migraines that effect my eyesight.  I have had total blindness before also and it is silver flickering lights that cover my field of vision.  With myself the more vision I loose the worse the pain.  My blindness will last usually 1/2 hour.  I couldn't imagine go through it every day.  I take meds now that controll the migraines it is Atenolol something that may not be able to be taken by children.