optic nerve
noun [ C ] anatomy specialized uk/ˌɒp.tɪk ˈnɜːv/ us/ˌɑːp.tɪk ˈnɝːv/
视神经（形如细丝的神经纤维束，将视觉信号从眼后部的视网膜传输至大脑）
the group of nerve fibres (= structures like threads) that pass signals from the retina at the back of each eye to the brain