The optic nerve in the human eye is a cable-like bundle of nerve fibres composed of the axons of ganglion cells, responsible for transmitting visual information to the brain’s lateral geniculate nucleus.
- This nerve contains about a million fibres that carry a constant stream of visual data, received from the eye’s photoreceptors—rods and cones—as well as intermediate neurons such as bipolar and amacrine cells.
- The optic nerve functions like a parallel communication cable, with each fibre transmitting distinct information about light intensity and patterns from specific regions of the visual field, allowing the brain to construct a cohesive image of the surroundings.
- The optic nerve exits the eye at a spot called the optic disc, where no photoreceptors are present, creating a natural “blind spot” in the visual field. The brain compensates for this by filling in the missing information.
- Some fibres from the optic nerve cross over to the opposite side of the brain at the optic chiasm. This crossover allows visual information from both eyes to be processed in both hemispheres of the brain, which is crucial for depth perception and a unified field of vision.