Definition

Noun: A condition of the visual system in which the perceived image of an object differs in size or shape between the two eyes. This defect can cause visual discomfort, headaches, and difficulty with depth perception.

Usage

"Aniseikonia" is a technical, medical term used almost exclusively in the fields of optometry and ophthalmology. It describes a specific type of binocular vision anomaly.

Examples

• The patient's persistent eyestrain and difficulty judging distances were diagnosed as being caused by aniseikonia.
• Corrective lenses were specially ground to minimize the aniseikonia resulting from the different prescriptions for each eye.
• Aniseikonia is a potential complication following certain types of eye surgery, such as cataract removal.

Advanced Usage

• Physiological aniseikonia: Refers to the normal, slight difference in image size between the two eyes, which the visual system typically fuses without issue.
• Optically induced aniseikonia: Caused by corrective lenses, especially high-powered prescriptions or when there is a significant difference (anisometropia) between the two eyes.
• Retinal aniseikonia: Caused by displacement or distortion of the retinal photoreceptors.

Variants and Related Words

• Aniseikonic (adjective): Pertaining to or affected by aniseikonia.
  • The optometrist prescribed aniseikonic lenses to correct the imbalance.

Synonyms

• Image size disparity
• Ocular image inequality

Note: There are no common, non-technical synonyms for this highly specific term.

Noun

1. visual defect in which the shape and size of an ocular image differ in the two eyes