The optic nerve: Features of functioning and typical diseases

Isn’t it funny when you watch cartoon characters with their eyes popping out each time they get shocked?

They hardly fall off basically because the eye balls are connected to chord-like structures in the sockets. These structures are called the optic nerves.

The optic nerve is part of the cranial nerve system (the nerves involved in the transmission of information in the head) comprised of 12 nerves. It emanates from the retina of the eye and moves to the visual nuclei found in the brain.

For Proper Eye Care, Know the Basic Functions of the Optic Nerve

The main function of the optic nerve is the transmission of visual information (comprising of color and brightness perception) from the eye’s retina to the brain through electric impulses.

Another function is to conduct visual impulses necessary for accommodation reflex and light reflex. As a result, they adjust the sizes of the eye lenses and pupils, respectively, in response to change in lighting.

Like many other parts of the body, the optic nerve is susceptible to diseases, most of which can result in severe or even total loss of vision.

Major Diseases of the Optic Nerves

The three most common optic nerve diseases are glaucoma, optic neuritis, and Anterior Ischemic Optic Neuropathy. 

1. Optic Neuritis

This is the inflammation of the optic nerve mainly caused by multiple sclerosis (a typical optic neuritis). The condition can be dichotomized into two – retrobulbar neuritis and optic papillitis.

While the cause of multiple sclerosis is yet to be fully explained, the deterioration of the immune system is often pointed as a factor behind the disease. A weak immunity can be caused by other diseases such as cancer, diabetes, and HIV.

However, records from National Center for Biotechnology Information show a rather interesting fact about optic neuritis. They found that this eye disease is common in regions far from the equator, with persons living along the equator being less susceptible to the condition.

Optic neuritis can either affect one or both eyes, and can either lead to partial or total blindness. The treatment of optic neuritis involves the administration (either intravenously or orally) of corticosteroid drugs.

2. Glaucoma

This is the most common ailment affecting the optic nerve and is also one of the leading causes of blindness. While glaucoma is a general eye condition, it mostly affects the optic nerves, especially in its advanced stages.

This effect on the optic nerve is professionally known as the “atrophy of the optic nerve.” This occurs when the increased pressure of the vitreous fluid squeezes the optic nerve and kills the cells that make up the nerve.

3. Anterior Ischemic Optic Neuropathy

Commonly known as AION, this condition is caused by insufficient blood supply to the optic nerve. Unlike other diseases affecting the optic nerve, AION rarely causes total blindness in a patient.

The main symptom of the condition is mostly exhibited when a person wakes up, and he/she experiences poor vision on one eye (normally obscured by a shadow). From that point, the vision progressively deteriorates.

Increased cholesterol, diabetes, and hypertension are some of the factors that are linked to AIOM incidences.

There is no known cure for AION. However, a study indicated that patients who received proper eye care early in the form of corticosteroid treatment for AION had improved vision soon thereafter.

Proper Eye Care Starts with You

There’s a common misconception that the optic nerve is part of the eye. It is, in fact, part of the central nervous system. It’s also the only part of the central nervous system that is externally visible.

For healthy eyes, you need to observe proper and regular eye care. If you notice anything wrong with your eyes, it’s best you see your eye doctor immediately.

Moreover, ensure you wear genuine and correct eyeglasses. Incorrect glasses is one of the leading causes of optic nerve damage.

For the best lenses and frames, has got you covered. 


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