Eye

I looked up eye transplants and came to a website http://www.mayoclinic.com/health/cornea-transplant/MY00491 describing what it was all about.

"A cornea transplant is a surgical procedure to replace part of your cornea with corneal tissue from a deceased donor. Your cornea is the transparent, dome-shaped surface of your eye that accounts for a large part of your eye's focusing power.
A cornea transplant can restore vision, reduce pain and improve the appearance of a damaged or diseased cornea. A cornea transplant, also called keratoplasty, is typically performed as an outpatient procedure.
Cornea transplant is the most common transplant operation performed in the United States. About 40,000 cornea transplants are performed each year, according to the Eye Bank Association of America."

After reading this I looked up the procedures of the operation. The first thing to be done is the eye is anesthetized so that the patient is calm and sleepy. They then clean the eye and put a drape over it. Surgery is then done using an Operation Microscope. The eye is kept open with stiches or a speculum. The corneal is then cut out from the donated eye, with a sugical equipment called a Trephine. The patients unhealthy cornea is replaced. The last thing done is the cornea is stiched to the patients eye with fine surgical thread.