How Performed: This test may be done in a health care provider’s office, a school, a work place, or elsewhere. Stand behind a line 20 feet from the eye chart. Remove glasses or contacts. Keep both eyes open and gently cover one eye with the palm of your hand, a piece of paper, or a paper cup while you read out loud the smallest line of letters that you can read on the chart. If you are not sure of the letter, you may guess. This is repeated with the other eye. Repeat the procedure while wearing glasses or contacts.

How To Prepare: Adults:
No special preparation is necessary for this test.

Children:
The physical and psychological preparation you can provide for this or any test or procedure depends on your child’s age, interests, previous experience, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child’s age:

• toddler test or procedure preparation (1 to 3 years)
• preschooler test or procedure preparation (3 to 6 years)
• schoolage test or procedure preparation (6 to 12 years)
• adolescent test or procedure preparation (12 to 18 years)

How It Feels: There is no discomfort.

Risks: There are no risks.

Why Performed: The test is performed when there are problems or changes in vision.

Normal Values: Visual acuity is expressed as a fraction. The top number refers to the distance you stand from the chart. This is usually 20 feet. The bottom number indicates the distance at which a person with normal eyesight could read the line with the smallest letters that you could correctly read. 20/20 is considered normal. 20/40 indicates that the line you correctly read at 20 feet could be read by a person with normal vision at 40 feet.

Abnormal Results: Abnormal results may indicate that you need corrective lenses to obtain normal vision.

Related topics:

• nearsightedness
• farsightedness
• presbyopia

Cost:

Special Considerations: Not applicable.