My Daughter Just Turned 6. We Went For Physical And

My daughter just turned 6. we went for physical and when the doctor tested her eyes we found out that her right eye was blurry to her. she was not able to read. Then we made an eye doc appointment. He gave her a glass with plus 3 power. My question is , can this be corrected as she grows older ? she will have to wear glasses for her life? How can I make sure her power does not go up?