The optic nerve allows you to see by carrying images from your eye to your brain. Optic neuritis involves inflammation of the optic nerve, which may cause sudden decrease or loss of vision. Optic neuritis is a serious condition that requires immediate care from your doctor.

The Optic Nerve

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The cause of optic neuritis is often unknown. Known causes of the diseases include:

  • An attack on the optic nerve by a viral infection or by the body's own immune system
  • Exposure to toxic substances such as lead

Risk Factors

The following factors increase your chance of developing optic neuritis. If you have any of these risk factors, tell your doctor:


Symptoms of optic neuritis include:

  • A sudden decrease in vision. Patients may describe this as blurred, dark, or dim vision, or as loss of vision in the center of, part of, or all of the visual field. In mild cases, it may look like “the lights are turned down.”
  • Abnormal color vision (dull and faded colors)
  • Pain in or around the eye, often made worse by movement of the eye.

Eye pain will often go away, usually within a few days. Vision problems will improve in over 90% of patients, though some may be left with blurred, dark, dim, or distorted vision. Vision improvement usually takes place over several weeks or months.


Optic neuritis may be difficult to diagnose, as your eye probably looks perfectly normal. Your doctor will ask about your symptoms and medical history, and will perform a physical examination. He or she should refer you to an ophthalmologist. Tests will include:

  • Tests of color vision, side vision, visual acuity, and the reaction of the pupil to light
  • A dilated eye examination to view the back of the eye (retina) with an instrument called an ophthalmoscope
  • Magnetic resonance imagining (MRI) may also be performed to look for certain medical conditions


Talk with your doctor about the best treatment plan for you. Treatment options include:

  • Steroid medications to reduce inflammation of the optic nerve
  • Certain other medications depending on other medical diagnoses
  • Observation


There is no known way to prevent a first episode of optic neuritis. The chance of having a repeat episode may be reduced if the first episode is treated with a steroid or other medication. It is very important to see an ophthalmologist immediately if you develop pain or decreased vision.