Nonpenetrating "blast injuries" to the eye in two patients resulted in multiple, small, corneal epithelial foreign bodies that were associated with characteristic ring-shaped opacities of the corneal endothelium. These endothelial lesions were clinically visible immediately after injury and became more pronounced during the next several hours. They disappeared within days and resulted in no permanent loss of visual acuity. This communication describes and illustrates the appearance of these endothelial lesions both clinically and in an animal model. Light and electron microscopic observations of an experimental model, with the use of monkey and rabbit eyes, revealed that the ring-shaped opacities resulted from swelling of the corneal endothelium, as well as accumulation of fibrin and leukocytes on the injured cells. Except for the epithelial impact site and the concussion injury of the endothelium, the cornea was uninvolved, and the stroma remained clear.