näköherman

The optic nerve, known in Finnish as the näköhermo, is a crucial part of the visual system. It is a bundle of over a million nerve fibers that transmit visual information from the retina to the brain. Each eye has one optic nerve, and these nerves partially cross at a structure called the optic chiasm, located at the base of the brain. This crossing ensures that the left visual field from both eyes is processed by the right side of the brain, and the right visual field by the left side.

The retina contains photoreceptor cells, rods and cones, which convert light into electrical signals. These signals are then processed by other retinal cells before being transmitted to the brain via the optic nerve. Damage to the optic nerve can lead to significant vision loss, ranging from blurred vision to complete blindness, depending on the extent and location of the damage. Common causes of optic nerve damage include glaucoma, optic neuritis, trauma, and certain tumors.

Diseases affecting the optic nerve are often diagnosed through various ophthalmological tests, including visual acuity tests, visual field testing, and optic nerve imaging such as optical coherence tomography (OCT). Early detection and treatment are vital to preserving vision when optic nerve issues are suspected. The intricate connection between the eye and the brain, facilitated by the optic nerve, is fundamental to our ability to perceive the world around us.