Myelinated Nerve Fibres

The insulating and protective fatty myelin sheath, which surrounds our nerves to protect and support them, doesn't generally enter the eye.
This myelination of the optic nerve develops embryologically in a posterior to anterior direction. The nerves are roughly myelinated in the intracranial and intracanal portions of the optic nerve by the seventh month (after conception) but doesn't usually reach the lamina cribosa until full term.
Sometimes this myelination continues into the eye, and is visible on the retina as bright white flame-shaped streaks which follow the course of the retinal nerve fibres and are situated superficially and often obscure the retinal blood vessels.

Do they affect vision? YES - they may cause field defects corresponding to their area of projection into the visual field. Should this person be driving? ...depends on their contralatteral eye!

This image demonstrates the path of the nerve fibre layer of the retina really well.