Differences Between an Eye Exam and a Contact Exam

An eye care practitioner must conduct an eye exam before prescribing corrective lenses. The type of exam varies depending upon whether the patient intends to wear glasses or contact lenses.

Eye Exam

• An eye exam measures a patient's visual sharpness by having her read an eye chart with one or both eyes. The patient also undergoes a retinoscopy test. The doctor places a machine before the eyes and flips magnifications until he finds a lens that is close to the right prescription. He fine-tunes the process with a refraction test. This test uses a different machine that contains several different lenses. The doctor questions the patient on which lens provides a clearer view.

Contact Lens Exam

• Contact lens exams evaluate the surface of the cornea to ensure that the contact lenses will fit correctly. The eye doctor uses a type of digital camera called a keratometer that measures the surface of the eye. He may also examine the cornea through a biomicroscope to make sure the eyes are healthy enough for contacts. Finally, the doctor selects an appropriate brand of contact lenses for the patient.

Considerations

• An eye doctor must perform a standard eye exam before evaluating a patient for contacts. Contact lens exams usually cost more than regular exams because of the extra time involved. Contact lens wearers are usually evaluated once a year for changes in vision.