Optic Nerve

Eye Anatomy

Optic Nerve

What is Optic Nerve?

A bunch of tissues that transmit signals from the eye to the brain are known as the optic nerve. The optical nerve is the main link between the eye and the brain. It is a bundle of one million nerve fibers and the tissue of the optic nerve is more related to the brain tissue than the nerve tissue.

Optic Nerve Latin Nervus Opticus
Gray's subject #197 882
MeSH Optic+Nerve

How Does the Optic Nerve Function?

It so happens that when the light gets into the eye, it first goes through the cornea. The cornea thus functions like a lens cover similar to a camera. Therefore when the light enters the cornea, it directs the light towards the pupil and iris. The pupil is the black tiny circle in the center of the eye and the iris is the colored part of the eye.

The pupil controls the amount of light that should enter the eye. It thus enlarges or dilates when there is less light around by allowing more light to enter the eye. The opposite happens when there is lot of light around, the pupil becomes small in size thus limiting the amount of light to enter the eye.

The light that enters the eye passes through the lens of the eye. The lens focuses the light entering to the back of the eye. This part of the eye is called the retina and it is a layer of nerve cells that is very sensitive to light. It transforms the light it receives to electrical impulses which is sent to the brain through the optic nerve. It so happens that the image and the light are upside down on the retina.

The optic nerve is a medium for the electrical impulses to pass to the brain. The optic nerve which is perceived by the brain thus helps in correcting the image.

Optic Nerve and Related Problems

Since the optic nerve is a medium between the eye and the brain, therefore any problem related to it may cause serious vision problems. There are a few problems related to the optic nerve and one such problem is optic nerve hypoplasia. This problem develops when the optical nerve does not develop completely during pregnancy. This can have mild to extreme vision impairment in either one or both the eyes.

The actual cause of optic nerve hypoplasia is not known and it is believed by doctors to be a hereditary condition. According to some studies, they indicate that there can be a link between mothers suffering with diabetes, alcohol abuse, maternal drug, use of anti-epileptic drugs and maternal age less than 20 years by expecting mothers. Researchers believe that all these may not be completely the cause of optic nerve hypoplasia.

There are conditions like injury, disease, hypertension, diabetes, alcohol, drug or tobacco abuse are capable of affecting the ability of the optical nerve to perform well thus causing blindness and vision impairment.