Eyeball: Optic Nerve and Visual Pathway

The human eyeball is a complex structure responsible for vision. The optic nerve and visual pathway play a crucial role in transmitting visual information from the retina to the brain.

Anatomy of the Optic Nerve

The optic nerve (cranial nerve II) is a bundle of over one million nerve fibers that connect the retina to the visual cortex.

Structure

• Retinal ganglion cell axons form the optic nerve.
• The optic nerve exits the eye at the optic disc.
• It passes through the optic canal in the sphenoid bone.

Visual Pathway

The visual pathway enables the brain to process images received by the eyes.

Components

• Optic nerve: Transmits impulses from the retina.
• Optic chiasm: Fibers cross for binocular vision.
• Optic tract: Sends signals to the lateral geniculate nucleus.
• Lateral geniculate nucleus: Relays information to the visual cortex.

Clinical Significance

Disorders affecting the optic nerve and visual pathway include glaucoma, optic neuritis, and stroke-related visual impairment.