Anisometropia: Definition and treatments
What is anisometropia?
Anisometropia (an-EYE-so-meh-TROW-pea-uh) is a vision condition in which one eye has more refractive error than the other. For example, one eye would be more nearsighted (myopic) than the other. So, that eye needs a significantly stronger lens correction than the other to see clearly.
The word anisometropia comes from the following Greek and Latin word roots:
Generally, anisometropia is considered present when there’s at least one diopter (D) of difference in refractive error between the two eyes. (The amount of nearsightedness or farsightedness and the amount of any astigmatism is considered.)
Prevalence of anisometropia
Anisometropia typically develops in childhood. One large vision screening of preschoolers in the United States found that 0.6% to 0.7% of children (age 7 or under) had anisometropia of 1.0 D or more.
However, a large Australian study of preschoolers (ages 6 months to 6 years) found a childhood anisometropia prevalence of 2.7%.
Anisometropia after cataract surgery
Though anisometropia typically develops in childhood, certain events can cause it to occur in adults.
Other causes of anisometropia occurring in adults include:
Antimetropia (an-TIH-meh-TROW-pea-uh) is a relatively rare type of anisometropia. In antimetropia, one eye is nearsighted and the other eye is farsighted.
Antimetropia poses significant risk of amblyopia and strabismus. It is treated the same as other forms of anisometropia.
Common symptoms of anisometropia include:
Treatment of anisometropia
Unequal retinal image sizes — a condition called aniseikonia (an-ih-si-KOH-nee-uh) — causes many of the same symptoms as uncorrected anisometropia.
By comparison, contact lenses and LASIK surgery produce clear retinal images with little or no discernable aniseikonia. This makes contacts and vision correction surgery the preferred treatment options for anisometropia.
For anisometropia after cataract surgery, your eye doctor might recommend a procedure called refractive lens exchange on the other eye.
The first step: Schedule an eye exam
Hofstetter, HW, et al., eds. (2000). Dictionary of Visual Science and Related Clinical Terms (5th ed). Boston: Butterworth–Heinemann.
Anisometropia. Merriam-Webster. Accessed December 2021.
Relationship between anisometropia, patient age, and the development of amblyopia. American Journal of Ophthalmology. July 2006.
Prevalence of anisometropia and its association with refractive error and amblyopia in preschool children. British Journal of Ophthalmology. September 2013.
Glossary — Aniseikonia through aphakia. Columbia University Department of Ophthalmology. Accessed December 2021.
Page published on Wednesday, December 15, 2021
Page updated on Wednesday, May 25, 2022