How the Test is Performed

First, you will be asked if you are having any eye or vision problems. You will be asked to describe these problems, how long you have had them, and any factors that have made them better or worse.

Your history of glasses or contact lenses will also be reviewed. The eye doctor will then ask questions about your overall health, including any medications you take and your family's medical history.

Next, the doctor will check your vision (visual acuity) using a Snellen chart.

• You will be asked to read random letters that become smaller line by line as your eyes move down the chart. Newer electronic devices have been developed that check vision in a way similar to a Snellen chart.
• To see if you need glasses, the doctor will place several lenses in front of your eye, one at a time, and ask you when the letters on the Snellen chart become easier to see. See also: Refraction test

Other parts of the exam include tests to:

• See if you have proper three-dimensional (3D) vision (stereopsis)
• Check your side (peripheral) vision
• Check the eye muscles by asking you to look in different directions at a penlight or other small object
• Examine the pupils with a penlight to see that they respond (constrict) properly to light

To see inside your eye, the doctor looks through a magnifying glass that has a light on the end (an ophthalmoscope). The device allows the doctor to see the retina and nearby blood vessels, back of the eye (fundus), and optic nerve area.

Often, you'll be given eye drops to open up (dilate) your pupils so that the doctor can view the structures in the back of the eye.

Another magnifying device called a slit lamp is used to:

• See the clear surface of the eye (eyelids, cornea, conjunctiva, sclera, and iris)
• Check for glaucoma using a method called tonometry

Color blindness is tested using multicolored dots that form numbers. See: Color vision test

How to Prepare for the Test

Make an appointment with an eye doctor (some take walk-in patients). Avoid eye strain on the day of the test. You may need someone to drive you home if the doctor uses eye drops to dilate your pupils.

How the Test Will Feel

The tests cause no pain or discomfort.

Why the Test is Performed

All children should have vision screening in a pediatrician's or family practitioner's office around the time when they learn the alphabet, and then every 1 to 2 years afterward. Screening should begin sooner if any eye problems are suspected.

Between ages 20 and 39:

• A complete eye exam should be done every 5 to 10 years
• Adults who wear contact lenses often need yearly eye exams
• Certain eye symptoms or disorders may require more frequent exams

Adults over age 40 who have no risk factors or ongoing eye conditions should be screened:

• Every 2 to 4 years for adults ages 40 - 54
• Every 1 to 3 years for adults ages 55 - 64
• Every 1 to 2 years for adults age 65 and older

Depending on your risk factors for eye diseases and your current symptoms or illnesses, your eye doctor may recommend that you have exams more often.

Various eye and medical problems can be found by a routine eye test, including:

• Cataracts
• Diabetes
• Glaucoma
• High blood pressure
• Macular degeneration

Normal Results

• 20/20 (normal) vision
• Ability to identify different colors
• Full visual field
• Proper eye muscle coordination
• Normal eye pressure
• Normal eye structures (cornea, iris, lens, etc.)

What Abnormal Results Mean

Abnormal results may be due to:

• Age-related macular degeneration (ARMD)
• Astigmatism
• Blocked tear duct
• Cataracts
• Color blindness
• Corneal abrasion (or dystrophy)
• Corneal ulcers and infections
• Damaged nerves or blood vessels in the eye
• Diabetes-related damage in the eye (diabetic retinopathy)
• Glaucoma
• Hyperopia
• Lazy eye (amblyopia)
• Myopia
• Presbyopia
• Strabismus
• Trauma

This list may not include all possible causes of abnormal results.

Risks

If you received drops to dilate your eyes for the ophthalmoscopy, your vision will be blurred and sunlight can damage your eye. Wear dark glasses or shade your eyes to avoid discomfort until the dilation wears off, usually in several hours.

Considerations

Many eye diseases, especially glaucoma and retinal detachment, are curable or can be treated if detected early.

Alternative Names

Routine eye examination; Eye exam - standard; Annual eye exam

References

Dermer JL. Eye movements and positions. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & wilkins; 2009:chap 2.

American Academy of Ophthalmology Preferred Practice Patterns Committee. Preferred Practice Pattern Guidelines. Comprehensive Adult Medical Eye Evaluation. San Francisco, CA: American Academy of Ophthalmology, 2010. Accessed January 17, 2011.

Olitsky SE, Hug D, Smith LP. Examination of the eye. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, Pa: Saunders Elsevier;2007:chap 618.

Update Date: 2/10/2012

Reviewed by: Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; and Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.