Discuss this with your pediatrician or/and see a pediatric ophthalmoloigst. Find one at www.aao.org
JCH MD
My sisters daughter had this problem at an older age - about 6 years old. The doctor said that normally it goes away after a while, but my sister was still very concerned. After another month, she again went to her doctor who recommended telling Jessica (the daughter) to "stop rolling your eyes" whenever she did it - in a kind and caring manner. Eventually it has slowed and stopped.
Maybe you could try this?
P.s. I'm not a Dr, I just know this from my sisters experience!