_______________ means there is a difference in the size or shape of the images seen by the left and right eyes.

_______________ means there is a difference in the size or shape of the images seen by the left and right eyes.

• A. Aniseikonia
• B. Anisometropia
• C. Diplopia
• D. Asthenopia

Answer: (A)

Aniseikonia is a difference in the perceived size or shape of images seen by the left and right eyes. This occurs when the two eyes' images are magnified or minified differently, so the brain receives two unequal pictures to fuse. A common cause is anisometropia—a mismatch in refractive error between the eyes—which can create a size mismatch in the retinal images, especially when wearing glasses or other corrective lenses that alter magnification. Because binocular fusion relies on similar image sizes, this mismatch can make fusion harder and reduce stereo vision, sometimes leading to discomfort or asthenopia as the eyes struggle to fuse the disparate images. In contrast, anisometropia simply refers to unequal refractive power without necessarily describing a perceptual size difference; diplopia is double vision from misalignment or lack of fusion, and asthenopia is eye strain.

Aniseikonia is a difference in the perceived size or shape of images seen by the left and right eyes. This occurs when the two eyes' images are magnified or minified differently, so the brain receives two unequal pictures to fuse. A common cause is anisometropia—a mismatch in refractive error between the eyes—which can create a size mismatch in the retinal images, especially when wearing glasses or other corrective lenses that alter magnification. Because binocular fusion relies on similar image sizes, this mismatch can make fusion harder and reduce stereo vision, sometimes leading to discomfort or asthenopia as the eyes struggle to fuse the disparate images. In contrast, anisometropia simply refers to unequal refractive power without necessarily describing a perceptual size difference; diplopia is double vision from misalignment or lack of fusion, and asthenopia is eye strain.