Multiple Sclerosis and Vision Problems

Vision problems—such as diminished vision, double vision, and blurred vision—are common in multiple sclerosis (MS), while a visual field cut is rare. This is because the disease often affects the optic nerves and the part of the brain responsible for eye movement, and less often the areas of the brain responsible for vision. Visual changes can be the first sign of MS and may linger for longer than other effects of the disease.

More than one of these structures can be involved at one time, and you may have more than one vision change as a result of your MS. In general, MS disease-modifying treatments (DMTs) are the best way to prevent visual deficits from occurring. Rehabilitation therapies may also be appropriate in some cases.

Symptoms

The vision changes in MS are most recognizable when they produce diminished vision or blurred vision. However, there are a wide variety of visual problems caused by MS, and you may also experience other associated effects, such as eye pain and dizziness.

MS can cause exacerbations (relapses) and may progressively worsen. The visual changes, similarly, can occur when you have a relapse or may worsen over time.

The most common MS-related vision alterations and their associated effects are:

• Diminished visual acuity: Decreased ability to read printed words or to recognize objects and people
• Scotoma: A blind spot in the center of your eye
• Eye pain: This can affect one or both eyes and typically worsens with eye movement
• Blurred vision: Hazy outlines or a sense that objects appear fuzzy
• Diplopia (double vision): Seeing an object as duplicated (the images can overlap)
• Dizziness and mobility problems: A feeling of being off-balance and unable to focus on objects
• Jerking appearance of objects: Nystagmus describes quick, jerky, involuntary horizontal or vertical eye movements that can make objects appear to be jumping or moving
• Headaches: Head pain that worsens with reading or is triggered by light

A visual field defect is not a common manifestation of MS, but can occur in patients with a large lesion involving the occipital lobe (the area of the brain responsible for vision). Loss of color vision, achromatopsia, is extremely rare, and it is not a usual characteristic of MS. Similarly, visual hallucinations, which involve seeing objects that are not there, can occur with dementia, psychosis, or as a medication side effect, but are not typical with MS.

Causes

MS is caused by demyelination, which is the loss of the protective myelin (lipid, fat) layer that optimizes nerve function. With the disease, the demyelination (and symptoms) can progressively worsen or may relapse and remit.

Several major structures that are necessary for maintaining proper vision can be affected by this process:

• The optic nerve controls vision, and when it is involved in MS, symptoms can include eye pain and decreased vision, including scotoma and visual field defects.
• The brainstem controls the nerves that mediate eye movement. Your eyes typically move in alignment with each other. Brainstem involvement in MS can affect eye muscle function, resulting in misaligned eye movements. This can make you think that you are seeing two objects instead of one.
• The cerebellum controls balance by mediating a number of important physical functions, including coordinated eye movements. When the cerebellum is involved in MS, nystagmus can result.

Headaches, dizziness, and blurred vision can occur when any of these structures are affected by MS.

Diagnosis

Identifying the visual changes in MS is not always straightforward. It may be difficult for you to know that you have a blind spot, or to know the difference between double vision and nystagmus, or between eye pain and headaches.

That's why it's important to get regular routine vision screenings if you have MS. Your eye care specialist can coordinate your care with your neurologist to treat and manage vision problems that may develop.

In these screenings, your eye healthcare provider will take a detailed medical history and may ask you questions about your vision, such as whether your visual problems come and go, whether you wear corrective lenses, and whether you see spots or floaters.

There are some ways that your healthcare provider can pinpoint your visual deficit and determine whether they are caused by MS or something else.

• Visual acuity examination: One of the things your healthcare provider may check is whether you can read letters at a given distance using an eye chart. Your results may be compared to your previous vision examinations if you had any.
• Eye movement check: Nystagmus can occur at any time, but your healthcare provider is more likely to see nystagmus than you are to notice it yourself. Sometimes, looking far to the right or left can make nystagmus more obvious. Your healthcare provider will also ask whether you see more than one object when you move your eyes to the sides and up and down (to identify diplopia).
• Visual field testing: Your healthcare provider will examine your ability to notice objects in all of your visual fields, including the center (to identify whether you have a scotoma). You may need to cover one eye at a time during a portion of this test.
• Visual evoked potentials (VEP): This is a non-invasive electrical test that measures your brain's response to light. An electrode that detects your brain's electrical activity is placed superficially on your scalp as you look at lights on a computer screen. The results can help your healthcare providers identify changes characteristic of MS.

Treatment and Prevention

Treatment and prevention are both important if you have visual problems with MS. As with the prevention of MS progression and relapses, preventing visual effects of MS relies on the use of DMTs and maintaining a healthy lifestyle.

Treatment of an Exacerbation

Treatment of a flare-up generally involves intravenous (IV) steroids. Plasmapheresis (plasma exchange to filter the blood) is an approach for severe MS exacerbations.

As with non-visual effects of MS, optic neuritis and brainstem or cerebellar lesions typically improve within 12 weeks.

The outcome is generally better if treatment of a flare-up, which often involves intravenous steroids, is initiated soon after symptoms occur.

Symptomatic Management

Anti-seizure medications and muscle relaxants may decrease MS-associated nystagmus if it is persistent. If you have double vision, your healthcare provider may recommend patching one eye or may prescribe temporary prism glasses until it resolves.

If your vision is reduced for a long time, even after the resolution of an MS exacerbation, you may need rehabilitation and occupational therapy to help you get around and function better.

The following tips may help you with daily tasks:

• Increase lighting in your home, especially in areas where you want to see better.
• Increase contrast around light switches, doorways, and steps with colored tape or paint.
• Consider large-print newspapers, books, and telephone keypads.
• When going out to the movies or dinner, locate the exits and bathroom, and carry a small flashlight.

A Word From Verywell

You may need to make some major lifestyle adjustments, especially if your vision affects your ability to drive. This may sound disappointing, but keep in mind that most of the time, symptoms of MS improve, at least partially. If you have had visual symptoms which have resolved, be prepared with a plan in case your symptoms act up again.