Optic nerve has myelin sheath (which was produced by oligodendrocytes ) except the ocular part . But there is an another CN which doesnt have any myelin at all. And that is nervus olfactorius .

In the ocular part of optic nerve , before it exits from lamina cribrosa sclera its not covered by myelin ,but after the lamina cribrosa there is myelin .

Dr. Fatemeh Kourkinejad

about 7 years ago

What was the optic nerve note? Maybe I have mistaken it.