Anisocoria is diagnosed by an ophthalmologist through an eye examination. During the diagnostic process, additional tests may be requested to evaluate symptoms and determine the underlying cause. Eye drops may be used during the examination to allow for a better assessment of the pupils. The following advanced diagnostic methods can be employed to thoroughly investigate the cause of anisocoria: Magnetic Resonance (MR) Imaging, Computed Tomography (CT) Scan, X-ray, Complete Blood Count.