A person with weak sight cannot see far.

视力差的人不能看得很远。

He suffers from weak sight and weak hearing.

他的视力听力都差。

He suffers from weak sight and weak hearing.

他的视力、听力等不太好。

He suffers from weak sight and weak hearing.

她的视力因年岁的增长而变差了。

What is weak sight and how can these be optically corrected?

什么是弱视？能通过光学镜片来校正吗？