A contact lens exam is a separate part of your comprehensive eye examination that requires some additional testing that people who do not wear contact lenses do not need to have. In order to prescribe contact lenses, your optometrist needs to evaluate the health of your eyes, paying close attention to how contact lens wear will affect the health of your eyes. The contact lens prescription is determined based on your glasses prescription, vision needs, and corneal health and curvature.
Contact lens prescriptions and glasses prescriptions are different. Your contact lens prescription is often a variation of your glasses prescription, but also includes the type of contact lens and the proper sizing of contact lens for your eyes.
Contact lenses are medical devices that can only be dispensed by a prescription. These prescriptions expire after one year. Your eyes go through gradual changes in size, shape, and physiology requirements while wearing contacts and these changes can affect the health of your cornea. For these reasons, it is recommended to have a contact lens exam annually.