Optic nerve is -
Second order neuron
First order neuron
Fouh order neuron
Third order neuron
each optic nerve stas from optic disc and extends up to optic chiasma where the two nerves meet. It is the backward continuation of the nerve fibre layer of retina , which consists of the axons originating from the ganglion cells ie second order neuron. Reference: textbook of comprehensive Opthalmology by AK Khurana.
Neuro-ophthalmology