Shandong Eye Institute, east China, announced Monday the successful transplant of a bio-engineered pig cornea into a human eye in late September.

"The patient's vision has gradually improved after a three month recovery period, which means the transplant was a success," said Zhai Hualei, director of the institute's cornea division.

Wang Xinyi, 60, had a serious corneal ulcer. He could only see moving objects within 10 centimeters.

"The doctors originally told me that my father might lose sight in one eye because there are not enough cornea donations," Wang's son said.

The transplant used a bio-engineered cornea named Acornea, the first such product to be accredited by the China Food and Drug Administration in late April.

"With the pig cornea as the main material, the product is devoid of cells, hybrid proteins, and other antigens. It retains a natural collagen structure with remarkable bio-compatibility and biological safety," said Zhai.

Cornea diseases are one of the biggest causes of blindness in China, blinding around 4 million people. New cases are increasing by 100,000 each year, however, only about 5,000 people receive a cornea transplant annually.

Beijing Tongren Hospital and Wuhan Xiehe Hospital, among others, have been conducting clinical trials of Acornea since 2010, recording a success rate of 94.44 percent, similar to the results seen with donated human corneas.

"This bio-engineered cornea may help millions of people to see again," Zhai said.