My daughter got her prescription glasses at age 8. Now she is 9 years old, she can not see the chalkboard clearly at shool. If my daughter need new prescripition glasses? Normally, how often should she have her eyes tested? Thanks!

Yes, she need new prescription glasses. You should let your daughter have her eyes tested first, and use her new prescription to buy new eyeglasses for her. Eye exams for children are extremely important, your daughter should have an eye exam at least once a year.