«مَا دَعَاكَ إِلَى التَّعَامِي؟»
What prompted you to feign blindness?
Al-taʿāmī denotes the act of presenting oneself as blind. Al-Ḥārith asks for the reason behind the performance, not for a diagnosis of eye disease.
Once Abū Zayd opens his eyes, the earlier appearance must be reassessed. Bystanders observed behaviour consistent with blindness; that observation alone did not establish actual blindness. The disclosure corrects an inference without erasing the earlier events.
“He cannot see” is a conclusion; “he presented himself as unable to see” is an observation.