Topical ocular anesthetic abuse is a serious disorder causing keratitis and persistent epithelial defects. It may be the result of either prescription by the patient's eye care practitioner, theft from the practitioner's office, or occult additives in therapeutic medications. The authors report observations of six individuals suffering from this disorder which suggest that persistent epithelial defects, corneal stromal ring infiltrates, disproportionate pain, and prescription or nonprescription substance abuse may be factors involved. Penetrating keratoplasty was required to treat corneal perforation in two patients, and permanent corneal structural damage was noted in two eyes. Two eyes had a relentless downhill course culminating in enucleation. Because five of the six patients were diagnosed and treated as having presumed Acanthamoeba keratitis during the course of their disease, topical ocular anesthetic use should be included in the differential diagnosis of chronic keratitis and may masquerade as Acanthamoeba keratitis. The authors believe that practitioners should not prescribe or dispense topical anesthetics and should avoid clinical settings which provide an opportunity for the theft of topical ocular anesthetics.