Hospital officials say two million people in India are blind because of problems of the cornea.

VOA: special.2009.03.30

He went ahead and had the surgery to have the replacement of the cornea.

后来，迈克继续冒险,接受手术换掉了自己的角膜。

斯坦福公开课 - 7个颠覆你思想的演讲课程节选

The cornea is the clear front part of the eye that transmits light.

VOA: special.2009.03.30

(Speaking) With LASIK,doctors use a laser to permanently change the shape of the cornea to improve vision.

VOA: standard.2010.03.03