What is the primary function of the optic nerve?

The primary function of the optic nerve is to transmit visual information from the retina to the brain. This nerve is crucial for vision because it carries the electrical signals generated by photoreceptors in the retina, responding to light, directly to the visual cortex in the brain where the information is processed and interpreted. This communication is essential for perception, enabling the brain to form images from light signals that we see in our environment. Without the optic nerve, visual information could not reach the brain, making it impossible to perceive sight.

Options involving measuring intraocular pressure, controlling eye movements, and producing tears refer to functions performed by different structures within the eye or associated systems. For instance, measuring intraocular pressure is typically done with tools like tonometers, eye movements are controlled by the extraocular muscles, and tear production is managed by the lacrimal glands. However, the core role of the optic nerve involves the transmission of visual information, solidifying its importance in the visual process.