cranial nerve morphology trait optic nerve morphology trait VT:0001330 Any measurable or observable characteristic related to the shape, structure, color or pattern of the second cranial nerve which is responsible for conveying visual information from the retina to the brain; it extends from the retina to the optic chiasma where part of its fibers become the optic tract and cross to the opposite side and pass to the geniculate bodies. Trait.ontology CN-II posterior eye segment morphology trait