Optic neuritis is a condition that affects the eye and vision, caused by inflammation of the optic nerve. The optic nerve is responsible for carrying light signals from the back of the eye to the brain so that we can see. When the optic nerve is inflamed, damaged, or infected, it can cause vision problems. The exact cause of optic neuritis is unknown, but it is believed to be caused by the immune system mistakenly attacking the optic nerve tissue, resulting in inflammation and damage to the myelin. Some of the common symptoms of optic neuritis include:

• Pain with eye movement
• Temporary vision loss in one eye
• Diminished vision
• Trouble distinguishing colors
• Vision that appears blurry
• Inability to see out of one eye
• Abnormal reaction of the pupil when exposed to bright light

Optic neuritis usually affects one eye, and the symptoms may appear suddenly or develop gradually over a few days. The symptoms can be worse when you are hot or very tired, such as when you exercise or take a bath. If optic neuritis is not treated, its symptoms can get worse.

To diagnose optic neuritis, an ophthalmologist will check your eyes thoroughly and do a thorough medical exam, evaluation of your eyes response to direct bright light, testing of visual acuity using the letter chart to see how well you can see, MRI scan of the brain, testing of the ability to differentiate color, and exam of the back of the eye, known as the fundus. Blood tests may also be necessary in some people with optic neuritis depending on the situation.

Optic neuritis may resolve spontaneously without treatment, but if visual function is poor, a course of IV steroids may be recommended to speed up recovery and reduce the risk of future attacks. It is essential to see an ophthalmologist if you have optic neuritis symptoms.