What condition occurs when images from the right and left eye differ by more than 5%?

Aniseikonia is a condition characterized by a significant difference in the perceived size of images between the right and left eyes, specifically when this difference exceeds 5%. This disparity can cause visual discomfort and problems with depth perception because the brain struggles to fuse the two images into a single three-dimensional perception. When the images vary in size, it can lead to difficulties in binocular vision, making it challenging for a person to coordinate their visual output effectively.

Understanding this condition is crucial in optical practices, particularly when dealing with patients who might present discomfort while wearing corrective lenses or with specific visual tasks that require precise depth perception. Recognizing the signs of aniseikonia can prompt further investigation and potential solutions, such as customized lenses that can address the discrepancies between the eyes.

The other conditions, such as anisometropia (which involves a difference in refractive error between the eyes), and monocular or binocular vision (which pertain to whether one eye or both eyes are being used for vision) do not specifically refer to the issue of image size perception and are therefore not correct in this context.