A corneal surgery or transplant is an operation in which part, or all, the cornea is removed and replaced with healthy corneal tissue from an individual who has died and donated their cornea for transplantation. Permission has always been obtained from the deceased prior to death or from his/her family. Without the generosity of these corneal donors, it would be impossible to perform transplant operations and give the gift of sight to hundreds of people each year. This operation is normally performed under a general anaesthetic although if the patient's general health is poor it can be performed using a local anaesthetic. Blood and other tests are sometimes performed to ensure patients are in good health for the general anaesthetic. The operation usually takes between 30 to 60 minutes. It involves the ophthalmologist removing a circular portion from the centre of the cornea and replacing it with a similar sized circular area from the donor's cornea, which is then stitched into place with very fine stitches (also called sutures). The surgery is performed with the help of a microscope. In some cases, other procedures such as cataract extractions and glaucoma operations may be done in combination with a corneal transplant. The diseased part of the cornea that has been removed is occasionally sent to a laboratory for examination under a microscope. Following the operation, some soreness in the eye may be experienced and usually, the eye is padded with a plastic protective shield taped over it. This is removed 12-18 hours following the surgery. f the superficial layers of the cornea are healthy but the deep layers (corneal endothelium) diseased then these can be replaced without removing the superficial layers. This is termed deep endothelial lamellar keratoplasty. The transplant requires no stitches to keep it in place, allowing a much quicker recovery and less induced astigmatism.