Which refractive amblyopia has the greatest risk of developing amblyopia?

• A. Isometropic hyperopia
• B. Isometropic myopia
• C. Anisometropic hyperopia
• D. Anisometropic myopia

Answer: (C)

An interocular difference in refractive error (anisometropia) makes the brain favor the eye with the clearer image and suppress the other. When that difference is due to hyperopia, the blur is more pronounced and harder to overcome with accommodation, so the suppressed eye receives poor visual input during critical development. This persistent suppression leads to a higher chance of amblyopia developing in the eye with the greater hyperopic error. In isoametropia, both eyes are similarly blurred, so one eye isn’t consistently suppressed, and anisometropic myopia, while risky, typically presents a smaller disparity than hyperopic anisometropia. Hence anisometropic hyperopia carries the greatest amblyopia risk.