In eye donation, specifically in corneal transplantation, the part of the eye that is transplanted from the donor is the cornea.

The cornea is the transparent, dome-shaped front part of the eye that covers the iris, pupil, and anterior chamber. It plays a crucial role in focusing light onto the retina, which is responsible for vision.

During eye donation, if the cornea is healthy and suitable for transplantation, it can be removed from the donor`s eye and transplanted into the recipient`s eye. This procedure is known as corneal transplantation or corneal grafting. The donated cornea replaces the damaged or diseased cornea of the recipient and helps restore vision.

It`s important to note that in eye donation, only the cornea is typically transplanted, not the entire eye. Other parts of the eye, such as the lens, retina, and other structures, are not commonly transplanted in the same way as corneal transplantation.

Therefore, the correct answer is:

Cornea.