Is the myelin sheath of optic nerve axons provided by schwann cells or oligodendroglia?

The retina and optic nerve are part of the central nervous system, as they are derived from the neural tube. We know that oligodendroglia provide myelin for the central nervous system and Schwann cells provide myelin for the peripheral nervous system. Therefore, oliogodendroglial cells must provide the myelin for the optic nerve.

The answer is Paramecium