She suffered from short sight.

她眼睛近视。

This is also a factor to short sight.

这也是一个因素，短期看不到。

And short sight may caused by it for your eyes stay tense.

眼睛长期处于紧张状态容易造成近视。

I feel I'm having short sight, so I have to go and have my eyesight tested.

我感觉我近视了，因此我得去检查一下视力。

Short sight comes about because the eye ball grows too big and fails to focus light properly.

近视的产生，是因为眼球长得过大，无法正常地集中光线。