In patients with dry eye, like pemphigoid, Fuchs-Stevens-Johnson syndrome and xerophthalmia, in eyes with severe vascularisation of the cornea due to severe burns, in a leucoma adherens or following recurrent transplant rejections as well as in cloudy corneas of silicone-filled eyes, restoration of visual acuity can often only be achieved by a keratoprosthesis. In the case of an intact posterior segment and retinal function a normal visual acuity can be anticipated but mostly with a restricted visual field. Complications vary from glaucoma, retroprosthetic membranes, necrosis of the recipient tissue at the rim of the prosthesis, endophthalmitis, loosening and loss of the prosthesis even to the loss of visual acuity. With some types of prostheses the visual acuity will be reduced again within a short time, but in osteo-odonto-keratoprostheses, using the root of a patients tooth as haptic material for the optical cylinder, good long-term results even for several decades are possible. In patients without suitable teeth, prostheses with biointegrable materials such as Pintucci keratoprostheses can be used. A basic rule is that a secondary glaucoma, which in this patient group frequently develops even preoperatively, must be treated adequately.