Eye surgery (image 4 of 6). Surgical scissors cutting a diseased cornea from an elderly woman's eye. The cornea is being held by forceps. It will be replaced by keratoplasty, the graft or transplantation of a cornea from a donor. She also has a cataract, a cloudy lens in her eye, that must be replaced with a lens implant (prosthesis). 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.