Anisometropia

This is a condition where the refractive error of the two eyes is different by more than ± 3. In low degrees of anisometropia, spectacles may be tolerated. In high degrees of anisometropia, i.e. above about three diapers, spectacles cause greatly dissimilar retinal images and become intolerable. Anisokonia is a condition of a difference in the magnification of images of both the eyes.

If there is also astigmatism along with anisometropia, it further results in distorted retinal images in addition to anisokonia. In these conditions contact lenses are the treatment of choice.