Anisocoria (Unequal Pupils) By Christopher J Brady, MD, Wilmer Eye Institute, Retina Division, Johns Hopkins University School of Medicine Reviewed / Revised May 2021 | Modified Sep 2022 View Patient Education Etiology Evaluation Treatment Key Points Topic Resources Anisocoria Due to Horner... Some Common Causes of Anisocoria Anisocoria is unequal pupil sizes.