The cornea is the most anterior transparent part of the eye, covering the iris, pupil and anterior chamber, and provides most of the refractive power for the eye. Together with the refractive power of the lens, light can be accurately focused on the retina to form an image. The cornea has the greatest refractive power of any refractive system in the human eye because it is in direct contact with the air. The cornea has very sensitive nerve endings, and if an external object touches the cornea, the eyelid will involuntarily close to protect the eye. In order to remain transparent, the cornea does not have blood vessels and receives nutrients and oxygen through tears and atrial fluid. Generally, corneal transplants are performed on a one-to-one basis, but with improved transplantation techniques, a single cornea can be used for multiple patients as long as the conditions are right. Because of the scarcity of corneal donors in China, our corneal transplant surgeons in China have the ability and must effectively utilize all parts of each donor cornea. The surgeon will generally cut and transplant the donor “site” according to the location and nature of the patient’s corneal lesion. Simply put, a corneal transplant is like “replacing a watch”, but not all of it is replaced because of the chance of rejection and the need for tissue healing. If the marginal foci are bad, only the peripheral parts are replaced; if the superficial layer is bad, only the superficial layer is replaced; if the deeper layer is bad, only the deeper part is replaced, which is the concept of “component corneal transplantation”. In the reality of domestic eye banks, after obtaining high quality corneal donors, they are generally used for “penetrating corneal transplantation” or “corneal endothelial transplantation” on a “one-to-one” basis. “The remaining “leftovers” are well preserved by the eye bank and used for other patients. This has led to the “one cornea for many patients” story that is being reported in the media. Therefore, the scientific argument is that “after screening by eye banks and clinicians, a pair of qualified corneal donors can save at least two patients”. What are the requirements for corneal donation? It can be said that “anyone” can donate a cornea. However, what the donated cornea is used for and whether it can be used clinically depends on eye bank testing and evaluation by eye bank technicians and clinicians. Eye banks have strict selection criteria for corneal materials used in clinical transplants. Absolute contraindications for donors include: AIDS, hepatitis B and C and other infectious diseases of blood origin; leukemia, malignant lymphoma and other hematologic malignancies; acute systemic and ocular infectious diseases, etc. Other “relative contraindications” for donors are also numerous and should be considered by the surgeon based on the recipient patient and eye bank donor test results. For those corneas that cannot be used clinically, eye banks use them for teaching or research, which is also of great significance to the development of medicine. For example, the “retinal pigment epithelial cell line”, which is now widely used in basic ophthalmic research worldwide, originated from a 19-year-old boy who died unexpectedly in the United States, and his contribution is worldwide.