Standards for an Eye Examination

Recent medical advancements in vision and eye research allow for an eye exam to serve several purposes in addition to obtaining an accurate prescription update for one's vision. Knowing what will happen during your eye exam will help you to prepare in advance for the time commitment, which can be from 30 to 90 minutes, depending on your vision needs and requirements.

Preliminary Information

• As a medical professional, an ophthalmologist or optometrist will typically give you a medical history interview and screening prior to your exam. Common questions may include those regarding your personal and family health history, age, current satisfaction with your vision, use of contacts or eyeglasses, current medications, allergies, history of glaucoma, diabetes or hypertension. The medical screening helps the doctor and staff at an eye exam know about your pertinent medical history and determine level of risk for vision disorders or diseases.

Visual Acuity Test

• A visual acuity test is typically given using an eye chart or a projected chart while you sit in the chair of an examination room. One such test involves an eye chart of the letter "E" facing different directions. Visual acuity is tested at a distance of 20 feet for distance vision and 16 inches for near vision and is performed one eye at a time.

External Examination Procedures

• An eye doctor will also perform a brief examination of the physical appearance of your eyes and face. The doctor will typically look unusual skin conditions on your eyelids and face and signs of eyelid inflammation, known as blepharitis. Blepharitis is indicated by redness and crusty debris at the base of the eyelashes. The doctor will also look for signs of conjunctivitis, also known as pinkeye, by looking at the whiteness of the eyes.

Other Exam Procedures

• Other procedures may include an eye alignment test, which uses an occluder to cover each eye while you focus on an object projected on the wall of the examination room. A pupil response test is also given, which measures the size and shape of your pupils as they adjust to changing light conditions. Autorefractors are commonly used to determine eyeglass lens prescriptions. Some doctors may use a phoropter, which contains thousands of lens combinations, for a subjective refraction test. A tonometer may also be used to test for glaucoma.