A comprehensive eye exam can help diagnose eye health problems while vision screening detects visual health issues. Children should undergo regular vision screening. A pediatrician or school nurse usually performs vision screening. It helps to monitor the child's development and can pick up problems with vision early enough. If a problem is detected via screening, the examiner will refer the child to an ophthalmologist for a comprehensive eye exam. With a comprehensive eye exam, the underlying problem is determined so the doctor can start appropriate treatment. However, if the child passes the screening test, no further action is required.