At this stage of corneal transplantation, the corneas taken are basically human corneas, which are donated by others for transplantation. Artificial cornea, at this stage, scientific research has discovered that a special optical device, an artificial cornea, can be made from transparent medical polymer material, which, in theory, can be surgically implanted into the corneal tissue to replace part of the corneal scar tissue, thus restoring vision. However, at this stage, the long-term results are not good because the rejection of the synthetic material by the corneal tissue is not well resolved. Some experimental treatments have been found to cause water leakage inside the eye at the transplantation site, and the transplanted artificial cornea can be detached, so it cannot be widely used yet. At this stage, the artificial cornea technology is not yet mature enough to be used in clinical practice.