What Constitutes a Comprehensive Eye Exam 

General vision screenings are usually administered by staff at school, pediatric offices or a regular physician's office. The primary purpose of this exam is to identify individuals who have undetected vision problems, then refer them for further evaluation with an optometrist. 

Vision screenings are limited in scope and are only meant as a preliminary test. The AOA cautions: "Even if a child or adult passes a vision screening, they shouldn't assume that they don't have an eye health or vision problem. Professional examinations are the only effective way to confirm or rule out the presence of any eye disease or vision problem." 

In contrast to a screening, a comprehensive eye exam is one performed by an optometrist or ophthalmologist using specialized equipment and procedures. The test administrator will have the specialized training needed to make definitive diagnoses and prescribe treatments.