<iframe src="https://www.googletagmanager.com/ns.html?id=GTM-KXVNDH86" height="0" width="0" style="display:none;visibility:hidden">

Optic nerve

nervus opticus, optic nerve bundle, facial nerve, optic nerve, second cranial nerve
The optic nerve, also known as the nervus opticus, is the nerve that connects your retina to your brain and transmits visual information. Without a properly functioning optic nerve, your brain cannot process the images captured by your eye.
Anatomy of the eye

What is the optic nerve?

The optic nerve is a thick bundle of nerve fibres that runs from the back of your eyeball to your brain. It is, in fact, an extension of your central nervous system. The optic nerve begins at the optic disc, the point where all the nerve fibres from your retina converge, and runs through an opening in the eye socket to the brain.

The optic nerve consists of around one million nerve fibres that transmit electrical signals. These signals are generated when light-sensitive cells in your retina are stimulated by light. The optic nerve transmits this information to the visual cortex in your brain, where the signals are converted into the images you perceive.

The optic nerve has a diameter of approximately 3 to 4 millimetres and is surrounded by protective layers. Part of the optic nerve lies within the eye socket, whilst another part runs through a bony canal in the skull. Because the optic nerve plays such a crucial role in your vision, damage to this nerve can lead to permanent vision problems.

Good to know

Disorders of the optic nerve

Various conditions can affect the optic nerve. In glaucoma, the nerve is damaged by increased intraocular pressure, which can gradually lead to vision loss. Inflammation of the optic nerve, also known as optic neuritis, can lead to pain when moving the eyes and temporary loss of vision. Tumours, circulatory problems or hereditary conditions can also affect the function of the optic nerve.

Examination of the optic nerve

Your optician, optometrist or ophthalmologist can examine the optic nerve by looking at the optic disc using specialised equipment. This examination assesses the colour, shape and depth of the optic disc. Abnormalities may indicate increased pressure within the eye, inflammation or other problems. Modern imaging techniques such as OCT (optical coherence tomography) can accurately measure the thickness of the nerve fibre layer.

Signs that require attention

Sudden loss of vision, blurred vision that does not improve with glasses or contact lenses, pain when moving the eyes, or seeing flashes or spots may indicate a problem with the optic nerve. These symptoms always require assessment by an ophthalmologist. Early detection of optic nerve problems is important, as some forms of damage are irreversible.

If you have any symptoms or are concerned about your eyesight, please have it assessed by your optician, optometrist or ophthalmologist.

Frequently asked questions

Damage to the optic nerve itself is not usually felt immediately, as the nerve has no pain receptors. However, you may notice changes in your vision, such as blurred vision, loss of peripheral vision or impaired colour vision. In some cases of optic nerve inflammation, however, pain may occur when moving the eyes. Regular check-ups with your optician or ophthalmologist help to detect problems at an early stage.

Recovery of the optic nerve depends on the cause and severity of the damage. In some cases of inflammation, the nerve may recover partially, but in other conditions such as glaucoma, the damage is permanent. Nerve fibres in the optic nerve cannot regenerate in the same way as some other nerves in the body. That is why early detection and treatment by an ophthalmologist are important to limit further damage.

The retina is the light-sensitive tissue on the inside of your eyeball, where images are captured. The optic nerve is the cable that transmits these images as electrical signals to your brain. You can compare it to a camera: the retina is the sensor that captures the image, and the optic nerve is the cable connecting to the computer that processes the image. Both are necessary for good vision.

Contact lenses sit on your cornea and do not come into direct contact with the optic nerve, which is located deep within your eye. Well-fitted and properly maintained lenses do not pose a risk to the optic nerve. However, it is important to have regular check-ups with your optician or optometrist so that any eye problems, including those affecting the optic nerve, can be detected in good time. Always wear your lenses in accordance with the instructions for use.

Author & updates

Author:
Publication date: 13 July 2026
Last updated: 13 July 2026