Energy-dispersive x-ray analysis (EDXA) was used to study nine intraocular lenses from one manufacturer. Residual polishing compound was found on two of three dry-sterilized lenses from a "hot lot" associated with a high incidence of sterile hypopyon. Similar material was not present on normal lenses. This polishing compound was apparently fused to the lens surface, preventing its removal by ultrasonic cleaning. In addition, three wet-sterilized lenses were found to be covered with small crystals containing barium. These crystals apparently resulted from leaching of the glass storage vial by the caustic storage fluid. It is suggested that some cases of sterile hypopyon following intraocular lens surgery may be caused by residual polishing compound present on the lens surface.