Optic Neuritis : Optic Nerve Disease : Symptoms & Causes

Optic neuritis is inflammation of the optic nerve. It may cause sudden, reduced vision in the affected eye.


  1. Loss of vision in one eye, over the course of an hour or a few hours
  2. Changes in the way the pupil reacts to bright light
  3. Loss of color vision
  4. Pain when you move the eye

Causes & Risk Factors

The cause of optic neuritis is unknown.
Sudden inflammation of the nerve connecting the eye and the brain (optic nerve) can injure the insulation (myelin sheath) surrounding each nerve fiber, causing the nerve to swell.

Causes of the inflammation can include:

  1. Autoimmune diseases (systemic lupus erythematosus, sarcoidosis,Behcet’s disease, autoimmune optic neuritis)
  2. Infections (tuberculosis, syphilis, Lyme disease, meningitis, viral encephalitis, and post-infectious measles, rubella, chickenpox, herpes zoster, mumps, and Mycoplasma pneumonia or other common upper respiratory tract infections)
  3. Multiple sclerosis (most often in adults, but also in children)
  4. Toxicity from drugs such as methanol or ethambutol
  5. Vitamin B-12 deficiency

Risk factors are related to the particular cause.

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