A Member of the University of Maryland Medical System | In Partnership with the University of Maryland School of Medicine
Email
Print
Home > Medical Reference > Encyclopedia (English)
Toggle: English / SpanishRefraction test - Results
Alternative Names
Eye test - refraction; Vision test - refraction; Refraction
Normal Values:
If your uncorrected vision (without glasses or contact lenses) is normal, then the refractive error is zero (plano) and your vision should be 20/20.
A value of 20/20 is perfect vision, meaning you are able to read 3/8-inch letters at 20 feet. A small type size is also used to determine normal near vision.
What abnormal results mean:
You have a refractive error if you need a combination of lenses to see 20/20. Glasses or contact lenses should give you good vision.
If your final vision is less than 20/20, even with lenses, then there is probably another, non-optical problem with your eye.
The vision level you achieve during the refraction test is called the best-corrected visual acuity (BCVA).
Abnormal results may be due to:
- Astigmatism
- Hyperopia (farsightedness)
- Myopia (nearsightedness)
- Presbyopia (inability to focus on near objects that develops with age)
Other conditions under which the test may be performed:
- Reviewed last on: 2/10/2011
- 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.
References
Katz M, Kruger PB. The human eye as an optical system. In: Tasman W, Jaeger Ea, eds. Duane's Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 33.
Kaufman JH. Subjective refraction: fogging and use of the astigmatic dials. In: Tasman W, Jaeger Ea, eds. Duane's Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 39.
Scott CA. Testing of refraction. In: Yanoff M, Duker JS, eds. Ophthalmology. 3rd ed. St. Louis, MO: Mosby Elsevier;2008:chap 2.8.
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.
American Academy of Ophthalmology Refractive Management/Intervention Panel. Preferred Practice Pattern Guidelines. Refractive Errors & Refractive Surgery. San Francisco, CA. American Academy of Ophthalmology, 2010. Accessed January 17, 2011.
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.
Related Articles
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).
Click to Print
Print Preview
© 2011 University of Maryland Medical Center (UMMC). All rights reserved.
UMMC is a member of the University of Maryland Medical System,
22 S. Greene Street, Baltimore, MD 21201. TDD: 1-800-735-2258 or 1.866.408.6885
