Jugglers don't focus on any 1 particular ball; they use this type of vision to keep track of the whole area
It is my opinion that balance training, in one form or another, should be ... time 
performing balancing training  even if you don't start until you ... focus to those 
studies that show the relationship between balance, .... (This means that the 
BOSU ball is useless, by the way, since we .... Why are they suboptimal?