Final answer:
The blow to the back of Phil's head likely caused damage to the occipital lobe, resulting in vision loss.
Step-by-step explanation:
The blow to the back of Phil's head most likely caused damage to the occipital lobe of the brain.
The occipital lobe is located at the back of the brain and is primarily responsible for vision-related functions, such as seeing, recognizing, and identifying the visual world.
Damage to this area can result in vision loss, which is consistent with Phil losing his vision after the blow.