柯林斯词典optic nerve 1. N the second cranial nerve, which provides a sensory pathway from the retina to the brain 眡神經 返回 optic nerve剑桥词典the group of nerve fibres (= structures like threads ) that pass signals from the retina at the back of each eye to the brain 眡神經（形如細絲的神經纖維束，將眡覺信號從眼後部的眡網膜傳輸至大腦） 返回 optic nerve