The information provided here is not a replacement for a doctor. You shouldn't use it for the purpose of self-diagnosing or self-medicating but rather so you can have a more informed discussion with a professional TCM practitioner.
Because it is a herb specifically indicated to treat corneal opacity as can be seen on Buddleia Flower's page.
Buddleia Flowers is a Cool herb that tastes Sweet. It targets the Liver.
Its main actions are: Clears Liver Heat and brightens the eyes.