Due to the inferno burning within one's eyes, those who practiced the Divine Eyes of the Ninth Netherworld would find their sensitivity toward colors fading as time passed, and eventually, the entire world would appear to be nothing but black and white to them.
Due to the nature of the injury, it was an irreversible symptom. There was no way to recover from it.
This was not listed in the flaws in the Library of Heaven's Path, but through Zhang Xuan's deep understanding of the Way of Medicine and cultivation, he could still deduce this much from working backward.
"Color blindness? What's that?" Sage Kui was stunned by the foreign term.
He had never heard that terminology from anyone's mouth before.
"You don't know what it is?" Zhang Xuan was startled for a moment before realization struck him.
Due to the difference in worlds, it was indeed possible that the notion of color blindness was not as prevalent or common in this world.