CN II: Optic Nerve

Question 1

Foramen?

Answer 1

Optic Canal

Question 2

Functions? (sensory, motor, parasympathetic, all three?)

Answer 2

Special sensory: sight

Question 3

How to test?

Answer 3

• Snellen chart (chart with incrementally smaller letters)

- pupillary eye reflex

Question 4

Pathology/disorders?

Answer 4

• Prechiasmatic lesions: unilateral blindness/unreactive pupil
• Bitemporal hemianopsia (peripheral blindness): caused by pituitary adema at optic chiasm
• Postchiasmatic lesion: homonymous hemianopsia (loss of left/right half of vertical midline)