That puts them at risk of losing their sight one day.

这使他们面临着有一天失明的危险。

At this point, the zombies rely on echolocation after losing their sight.

在这一阶段，僵尸失去视力后依靠回声定位。

They may need medicine for their eyes every hour to avoid losing their sight.

他们可能需要每小时为他们的眼睛吃药，以避免失去视力。

People with the disease usually start losing their sight before they are 18. This often progresses to total blindness.

这种疾病的患者通常在18岁之前会丧失视力，这往往会导致彻底失明。

Like many people who've lost their sight gradually, I had my doubts as to whether I'd be able to feel, let alone decode the tiny dots that he used in braille.

像许多逐渐失明的人一样，我怀疑自己是否能感觉到，更不用说解读他用盲文写的那些小点了。

Because Charles Bonnet Syndrome only occurs in people who had normal vision and then lost their sight, not those who were born blind, scientists think the brain uses remembered images to compensate for the lack of new visual input.

由于这种病症只发生在后天失明的人身上，先天失明的人并不会患上该疾病，科学家认为大脑使用了记忆中的图像，来弥补新视觉信息的缺失。

People with the disease usually start losing their sight before they are 18.This often progresses to total blindness. The gene that causes the disease could suddenly appear when a child is born with a copy of the gene from both parents.

患有这种疾病的患者通常会在18岁前丧失视力，通常会逐渐完全失明。当孩子遗传了来自父母双方的这种致病基因时，这种基因可能会突然显现。