What does anisometropic mean?
Anisometropic is a technical adjective used in optometry and ophthalmology to describe a condition in which a person's two eyes have noticeably unequal refractive power — for example, one eye may be nearsighted while the other sees normally, or both may be shortsighted but by very different degrees. The word derives from anisometropia, the noun for the condition itself, and appears most often in clinical contexts such as 'anisometropic amblyopia', where the visual system suppresses input from the weaker eye during development. Because even modest differences between the eyes can interfere with binocular vision, identifying someone as anisometropic has real diagnostic weight: uncorrected cases in childhood can lead to permanent lazy eye, while in adults the mismatch can cause eyestrain and poor depth perception. Though unfamiliar to most lay readers, the term is standard vocabulary for eye-care professionals and anyone researching uneven prescriptions.
adjectiveRelating to or characterized by anisometropia, a condition in which the two eyes have unequal refractive power, so that they require different lens prescriptions.
- Describing a person or eye pair in which the two eyes have significantly unequal refractive error (e.g., one myopic and one emmetropic eye).
- Relating more generally to anything connected with the condition of anisometropia, as in clinical terms such as 'anisometropic amblyopia'.
"The optometrist noted that the child was markedly anisometropic, with one eye nearly two dioptres stronger than the other."
"Because she was strongly anisometropic, her brain had learned to suppress the blurrier image from her left eye."
"Untreated anisometropic children are at elevated risk of developing amblyopia in the weaker eye."
If your two eyes need wildly different prescriptions, you're anisometropic — and your brain may have been quietly favouring one eye your whole life without telling you.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of anisometropic
Anisometropic comes from anisometropia, a nineteenth-century clinical term built from Greek roots: 'anisos' (unequal), 'metron' (measure), and 'trope' (turning), together literally meaning 'unequal turning of the eye's measurement'. The adjective simply attaches the standard English adjectival suffix '-ic' to that noun. Its closest relatives are other medical and scientific coinages sharing these Greek elements, such as anisotropic (properties varying by direction) and isometric (equal measure).
Related word forms
How anisometropic is actually used
Strictly a technical term used in optometry, ophthalmology, and vision science; it rarely appears outside clinical literature or patient reports. It is almost always applied to people's vision rather than used figuratively.
Easily confused with anisometropic
Anisometropia is the noun naming the condition itself, while anisometropic is the adjective describing something that exhibits or relates to that condition.
Anisotropic describes materials whose properties vary with direction (as in physics), whereas anisometropic describes eyes with unequal refractive power.