«مَا دَعَاكَ إِلَى التَّعَامِي؟»
What prompted you to feign blindness?
Mā daʿāka seeks a motive. Al-Ḥārith has already observed Abū Zayd seeing normally. The question is not “are you blind?” but “why did you choose to simulate blindness?”
Al-taʿāmī indicates an assumed or feigned condition. Reading it as an eye disease would dissolve the point of the exchange. The surrounding observation supplies what the interrogative itself leaves unstated: a disguise has already been exposed.
Practice: What answer is sought? A motive for disguise, not a medical history.