Optic neuritis results from inflammation of the optic nerve, the nerve that transmits information from the eyes to the brain, or from lesions that form along nerve pathways responsible for eye movement and visual coordination. It can be common in people with MS, but like most disease-related vision problems, it is highly treatable and often improves on its own. Optic neuritis is linked to MS because the disease damages nerves, including the optic nerve. It can be the first sign of MS, or it can develop later in the course of the disease. Its exact causes, however, aren’t known. Symptoms of optic neuritis Symptoms vary among people, and can range from blurred vision to a complete loss of sight. Usually only one eye is affected. A scotoma, or dark spot, might also appear at the center of your vision. Or, flashes of light may appear, especially when moving the eyes. Color vision may also be affected, with colors looking darker or washed out. Optic neuritis can, for some, be painful, especially with eye movement. The pain should not be too intense (affecting sleep) or last more than a few days — if it does, other causes might be involved. Diagnosing optic neuritis Optic neuritis is typically diagnosed by an ophthalmologist or a neurologist through routine examinations that may include ophthalmoscopy to evaluate the optic disk, which can be swollen in people with this condition; and a pupillary light reaction test. Upon suspecting or diagnosing optic neuritis, a specialist may request blood tests to check for antibodies for neuromyelitis optica, a central nervous system disorder; an optical coherence tomography (OCT) test to measure the thickness of the retinal nerve fiber layer, which is thinned in optic neuritis; visual evoked potentials, a test that evaluates how well the optic nerve is working by checking how long it takes the brain to react to a visual sign; and an MRI scan (magnetic resonance imaging) of the optic nerve to look for signs of inflammation. Treating optic neuritis Optic neuritis usually improves on its own, often within a few weeks. When symptoms are severe or affect both eyes, or if a quicker recovery is needed, intravenous steroids, such as methylprednisolone, are usually used. Most people recover close to normal vision within 12 months after an optic neuritis episode. Recurrent episodes of optic neuritis may predict a greater risk of developing MS in those without this disease. Note: Multiple Sclerosis News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.