如果得不到治疗，这种疾病可能导致永久性失明。

The disease can lead to permanent ___blindness if left untreated.

除了失明，他还面临着其他的健康挑战。

Apart from his ___blindness, he faces other health challenges.

这部纪录片探讨了突然失明所带来的情感冲击。

The documentary explored the emotional impact of sudden ___blindness.