Eye surgery (image 5 of 6). Forceps placing a lens implant (prosthesis) into an elderly woman's eye to treat a cataract (opaque lens). Retractors are holding her eye open. She also has a diseased cornea, which will be replaced by keratoplasty, the graft or transplantation of a cornea from a donor. 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.