PURPOSE: To characterize the presentation of diffuse interface keratitis after laser in-situ keratomileusis (LASIK), METHODS: Case report. RESULTS: Diffuse interface keratitis occurred in the left eye of a postoperative LASIK patient after central epithelial debridement without exposure of the flap margin or elevation of the flap. CONCLUSION: Diffuse interface keratitis is a nonspecific presentation of corneal inflammation after LASIK, with accumulation of inflammatory cells in the potential space bf the interface. Diffuse interface keratitis after LASIK may have multiple causes. (C) 2000 by Elsevier Science Inc. Al; rights reserved.