Asthenopia, Aniseikonia, and Cyclophoria

Several methods are used to measure cyclophorias although little is generally done to correct them. It can be shown that what is actually being measured is a rotational disparity between ocular images and that usual methods of measurement fail to distinguish between cyclophorias and oblique meridional aniseikonia, which can also create a rotational disparity. A method of distinguishing the difference between these conditions is described as it may be accomplished in the clinical setting, as well as the diagnostic value of these measurements in the prescribing of spectacles.