We report a case of an acute endothelial failure after the implantation of a new cosmetic, colored, artificial iris diaphragm implant called NewIris(®). A 21-year-old woman came to us complaining of progressive loss of vision and pain after NewIris lenses had been implanted. Decreased visual acuity, corneal edema, and increased intraocular pressure in both eyes appeared only 3 weeks after the surgery. The lenses were removed as soon as possible but had already severely affected the endothelial cell count. NewIris implants are an alternative to cosmetic contact lenses, but they are not as safe as other phakic anterior chamber intraocular lenses, nor are they a good option for the patient.