Princess Huanzhu 2 Why is Wei Zi blind?

There is no such episode in the new version of Princess Zhu Huan, but only in the old version. In episode 36 of the second part, Erkang and others came to Luoyang. First, they quickly found a doctor who specializes in ophthalmology. When Erkang asked for directions, Swallow let the blind Ziwei go out of curiosity about roadside chess. Ziwei was scattered by the crowd in the street, and he left the sight of the swallow. It never rains but it pours, and I was caught again. The swallow lost the crape myrtle, and Erkang was very angry with the swallow!