We present the case of a 27-year-old man with severe pain, loss of visual acuity, corneal edema, and high intraocular pressure (IOP) in 1 eye after bilateral Acrysof Cachet phakic intraocular lens (pIOL) implantation. Slitlamp examination was limited due to severe corneal edema, but anterior segment optical coherence tomography indicated upside-down implantation of the pIOL. The pIOL was explanted, which confirmed that the haptic indicator had been implanted counterclockwise. Postoperative treatment included antiinflammatory and antiglaucoma topical therapy. Follow-up monitoring showed decreasing corneal edema and normalized IOP. At 6 weeks, the corrected distance visual acuity was +0.1 logMAR, the IOP was within normal limits, and the cornea showed no signs of edema, but there was endothelial cell density loss. This case presents the preoperative and postoperative management of high IOP after pIOL implantation and illustrates the pitfalls of incorrect implantation of angle-supported anterior chamber IOLs with haptic angulation.Mr. Klaproth received travel reimbursement and/or lecture fees from the following companies: Alcon Laboratories, Inc., Bausch & Lomb, Neoptics AG, Rayner Intraocular Lenses Ltd., and Schwind eye-tech-solutions GmbH and Co. KG. Dr. Kohnen received travel reimbursement and/or lecture fees from the following companies: Alcon Laboratories, Inc., Abbott Medical Optics, Inc., Bausch & Lomb, Carl Zeiss Meditec AG, Neoptics AG, Rayner Intraocular Lenses Ltd., Schwind eye-tech-solutions GmbH and Co. KG. He is a consultant to Alcon Laboratories, Inc., Carl Zeiss Meditec AG, Rayner Intraocular Lenses Ltd., and Schwind eye-tech-solutions GmbH and Co. KG. No author has a financial or proprietary interest in any material or method mentioned.