translation.en: Blindness, the same thing. The key to discovering blindness is doing epidemiological surveys and finding out the causes of blindness, so you can mount the correct response.
translation.zh: 失明也是同样的道理。发现失明的关键是 做传染病调查，并且发现致盲的原因 只有这样，我们才能找到正确的应对方法