Aniseikonia: A condition in which the ocular image of an object as seen by one eye differs in size and shape from that seen by the other.Vision Tests: A series of tests used to assess various functions of the eyes.Lenses: Pieces of glass or other transparent materials used for magnification or increased visual acuity.Epiretinal Membrane: A membrane on the vitreal surface of the retina resulting from the proliferation of one or more of three retinal elements: (1) fibrous astrocytes; (2) fibrocytes; and (3) retinal pigment epithelial cells. Localized epiretinal membranes may occur at the posterior pole of the eye without clinical signs or may cause marked loss of vision as a result of covering, distorting, or detaching the fovea centralis. Epiretinal membranes may cause vascular leakage and secondary retinal edema. In younger individuals some membranes appear to be developmental in origin and occur in otherwise normal eyes. The majority occur in association with retinal holes, ocular concussions, retinal inflammation, or after ocular surgery. (Newell, Ophthalmology: Principles and Concepts, 7th ed, p291)Ocular Physiological Phenomena: Processes and properties of the EYE as a whole or of any of its parts.Diagnosis, Computer-Assisted: Application of computer programs designed to assist the physician in solving a diagnostic problem.Vision, Binocular: The blending of separate images seen by each eye into one composite image.Lenses, Intraocular: Artificial implanted lenses.