Nägemisnärv

The optic nerve, known in Estonian as the nägemisnärv, is a crucial component of the visual system. It is responsible for transmitting visual information from the retina to the brain. Composed of over a million nerve fibers, these fibers are actually the axons of the retinal ganglion cells. The optic nerve is approximately 50 millimeters long and connects the posterior part of the eyeball to the optic chiasm, a X-shaped structure located at the base of the brain.

At the optic chiasm, fibers from the nasal half of each retina cross over to the opposite side of the brain, while fibers from the temporal half remain on the same side. This arrangement ensures that information from the left visual field of both eyes is processed by the right side of the brain, and vice versa. After the chiasm, the nerve fibers continue as the optic tracts, which lead to various visual processing centers in the brain, primarily the lateral geniculate nucleus of the thalamus. From the thalamus, signals are relayed to the occipital lobe, where they are interpreted as vision.

Damage to the optic nerve can result in significant vision loss, ranging from blurred vision to complete blindness, depending on the extent and location of the injury. Conditions such as glaucoma, optic neuritis, and trauma can affect the optic nerve. Early detection and treatment are vital to preserve vision and prevent further damage.