What does it mean that Tik Tok tea can improve vision?

Drinking tea can make your eyes brighter. Tea can improve eyesight is a stalk, which originated from the fact that when Zhuge Liang, a strategist of Shu State, led his troops to Xishuangbanna during the Three Kingdoms period, the soldiers could not see clearly because of the acclimatization. Later, Zhuge Liang's rattan grew a tea tree on the ground. The soldiers' eyes brightened after drinking the tea collected by this tea tree. This stalk is used to describe that drinking tea can make your eyes brighter.