What Is an Eye Refraction Test?

The refraction test, also called eye test or vision test, is a simple procedure performed by an eye doctor to check a person's eyesight. The refraction test determines the prescription of contact lenses or eyeglasses.

Procedure

• The eye doctor asks the patient to read from a chart (around 20 feet away) while looking through a refractor (or phoroptor). The doctor changes the lenses in the refractor to choose the one that best suits the patient.

Considerations

• People who have vision problems should take the test every two to three years to determine if they need a new prescription. People over the age of 40 should take the test more frequently.

Normal Result

• The normal result of the refraction test is 20/20 vision, which means that the person has perfect vision.

Abnormal Results

• An abnormal result may mean that the person has one of the following vision problems: nearsightedness, farsightedness, astigmatism, or presbyopia.

Other Conditions

• The refraction test can also help the eye doctor determine if the person suffers from the following: ulcers or infections of cornea, detached retina, damaged retina, macular degeneration or blockage of blood flow to the retina.