Eye surgery (image 6 of 6). Corneal transplant being stitched (sutured) onto an elderly woman's eye. Retractors are holding her eye open. Her diseased cornea has been replaced by this donor cornea during keratoplasty, corneal graft surgery. She has also had an artificial lens (prosthesis) implanted to replace her cataract (opaque lens). The cornea is a transparent membrane over the front of the eye that focuses entering light. The light is then finely focused deeper in the eye by the lens. For a sequence of this surgery see images M570/116-121.