Purpose: To describe two cases of bilateral acute iris transillumination following systemic administration of moxifloxacin and review the literature.Methods: Review of clinical records, and review of the literature using the PubMed database.Results: A 75 year-old man and 33 year-old woman presented with bilateral conjunctival injection, photophobia, and atonic, distorted pupils. The symptoms began acutely following a respiratory illness, for which both were treated with moxifloxacin. Both patients demonstrated profound iris transillumination, sectoral posterior bowing of the iris, corneal endothelial pigment dusting, and trabecular meshwork hyperpigmentation. One patient had a cotton-wool spot. A literature review identified 59 previous reports in 5 publications, including 17 patients with no antecedent fluoroquinolone use.Conclusions: Increased awareness of this recently described clinical entity should lead to a decrease in unnecessary diagnostic evaluations. It is currently unclear whether this disease represents an adverse effect of fluoroquinolone use or a sequela of a systemic illness.