eyesight可數嗎

　　例句：

　　His eyesight is getting dim.

　　他的視力越來越差。

　　Her eyesight is failing.

　　她的視力日漸衰退。

　　He was not a particularly good shot because of his eyesight.

　　他由于視力緣故并不是一個特別好的射手。