Damage to the optic nerve is incurable, according to MedlinePlus. When the optic nerve is damaged, the person's vision dims over time, and his field of vision is narrowed. Eventually, the person no longer sees fine detail, such as words in a book, and color vision also fades.
Eventually the eye is not be able to respond to light as it did in the past, and the person may lose his vision altogether, explains MedlinePlus.
Many things damage the optic nerve, including injury. It is damaged by diseases such as glaucoma, where elevated pressure inside the eye injures the optic nerve. The optic nerve is also damaged by cranial or temporal arteritis, notes MedlinePlus. This is a condition where the blood vessels that serve the head are inflamed or damaged. Other conditions that damage the optic nerve include brain tumors, toxins, radiation, strokes and multiple sclerosis. The cause of optic nerve damage in some people is genetic, but this is rare.
Since there is no cure for optic nerve damage, the best course of action is to stop it before it worsens. This means the underlying disease needs to be treated. Therefore, it's important for people to have regular eye and other health exams with their doctor.