Final answer:
A patient with CN₃ palsy would exhibit diplopia, ptosis, an 'down and out' eye position, and pupil dilation due to disrupted function of most extraocular muscles and parasympathetic fibers of the third cranial nerve.
Step-by-step explanation:
A patient presenting with CN₃ palsy, also known as third cranial nerve palsy, would exhibit several characteristic symptoms. These include diplopia (double vision), ptosis (drooping of the upper eyelid), an eye that is positioned 'down and out', due to unopposed action of the lateral rectus and superior oblique muscles, and pupil dilation, as the parasympathetic fibers running along the third cranial nerve are affected, leading to a loss of pupillary light reflex and accommodation. Because CN₃ (oculomotor nerve) innervates most of the extraocular muscles, its dysfunction can impact both eye movements and pupil size, potentially resulting in significant visual disturbance.