Myelination of the optic nerve begins when?

• A. Prenatally
• B. At birth
• C. Postnatally, progressing through early childhood
• D. In adolescence

Answer: (C)

Postnatal myelination of the optic nerve begins after birth and continues through early childhood. This process starts behind the lamina cribrosa and progresses anteriorly along the nerve as oligodendrocytes lay down myelin, gradually increasing conduction speed along the visual pathway. The timing fits with how visual development unfolds, with slower transmission early on that becomes more rapid as the nerve becomes more fully myelinated in early childhood. Prenatal onset would imply myelination starts before birth, which isn’t typical, while starting at birth or not completing until adolescence doesn’t align with the common developmental window.