refractive errors
Last reviewed 01/2018
Refractive errors are abnormalities in the way light from a distant object is focused - via convergence of rays at the convex cornea and lens - onto the retina.
Ametropia means literally without ideal focus, and is a blanket term referring to all refractive errors.
Treatment of refractive errors is with spectacles or contact lenses. Note that binocular single vision is prevented where there is an image size difference between the eyes of 8% - corresponding to 3 or 4 dioptres difference in spectacles. Thus, eyes that are this different warrant contact lenses.