Answer: Bell's Palsy
Explanation:
Bell's palsy: This condition causes sudden weakness in the muscles of one side of the face, often leading to facial paralysis or numbness. It can also cause headaches, and tearing of the eye on the affected side due to the inability to close the eyelid completely. Based on Marc's symptoms, the most likely diagnosis is Bell's palsy. The sudden onset of facial numbness, headache, and eye-watering are all consistent with this condition.
The practitioner would likely diagnose Bell's palsy, considering Marc's symptoms.