Optic neuritis is a condition that affects a person's optic nerve, which connects the eye to the brain. It causes inflammation and damage to this nerve, leading to problems with vision, such as blurriness or loss of sight. Full definition
And then about 18 months later I developed optic neuritis [which can cause eye pain and vision problems], and that's what prompted me to go to the doctor. (health.com)
What they determined after further tests, however, was that she had multiple sclerosis, an autoimmune disease that affects the brain and central nervous system and was causing optic neuritis, an inflammation of the optic nerve that can cause a partial or complete loss of vision. (sciencedaily.com)
More than half of people with MS experience a vision problem called optic neuritis. (webmd.com)