Tafsir of Al-Balad 90:8

(Have We not made for him two eyes)
The interrogation here is for the purpose of affirmation and acknowledgment of favor. "Two eyes" refers to the organs of sight by which he perceives the visible realm.

(By which he sees)
The "by which" indicates that these are instruments for the act of seeing. This phrase serves to confirm the benefit and the utility of these organs, emphasizing that their creation was not in vain, but rather a profound manifestation of divine artistry and a means for the human to witness the signs of their Creator and navigate their existence.