How does multiple sclerosis affect your eyesight?
26 August 2021
What is multiple sclerosis?
Multiple sclerosis, also known as MS, is described by the National MS Society as “an unpredictable disease of the central nervous system that disrupts the flow of information within the brain, and between the brain and body.” The NHS describes MS as a lifelong “condition that can affect the brain and spinal cord, causing a wide range of potential symptoms, including problems with vision, arm or leg movement, sensation or balance.” Although the disease is one for which there is no cure, it typically comes in waves with periods of minimal to no symptoms, before the patient experiences a relapse.
As described above, MS can affect a range of your body parts, including your limbs and balance but the first symptom that people with MS usually notice is changes to their vision. MS-related eye changes commonly include:
- Blurry vision
- Involuntary eye movements
- Double vision
- Optic neuritis
- Loss of vision
Thankfully, vision problems that come from MS are usually temporary and your sight typically will return to its usual state, but the time this takes can vary depending on the individual and the severity of their MS. Read on to learn more about how MS can affect your vision, and discover what you need to look out for when it comes to your eye health.
What are the impacts of MS on your eyes?
If you have MS, you may experience any one or a combination of the symptoms we mentioned above. We’re going to delve into why each of these problems occurs and how they might manifest themselves.
Blurred vision usually occurs as a symptom of optic neuritis (which we’ll discuss later). If there is a lack of coordination in the eye muscles, the eyes will struggle to focus properly, resulting in blurry vision. Alternatively, a damaged optic nerve, occurring due to inflammation in the eye, can also cause blurred vision. This problem is usually temporary and your vision, in most cases, returns to normal but for some MS patients, slightly blurred vision could become a permanent fixture.
Nystagmus (jerky eye movements):
A particularly unsettling visual symptom of MS is the development of nystagmus, a condition characterised by jerky, involuntary eye movements. In rare cases it might be severe enough to prevent you from seeing properly, but in most cases it’s harmless – if very annoying – and painless. Sadly, there is no treatment for nystagmus but, when it presents in MS patients, it usually only occurs during a flare-up of the condition. Nystagmus can occur both when you’re moving your eyes and when you’re looking straight ahead, and you may find that holding your head at an angle helps reduce symptoms.
With MS comes a weakening or incoordination of eye muscles which can result in double vision, also known as diplopia. As with other symptoms of MS, double vision may be worse when you are experiencing a flare-up, followed by the symptoms gradually disappearing as your MS relapse period comes to an end. However, for some people, it can be a permanent visual change. Diplopia can usually be treated with a short course of steroids, or with specialised glasses with prisms to help minimise the effects of the condition. Some doctors, depending on the patient, may also suggest covering one eye with a patch to stop the double vision. However, this is not a long-term solution as it encourages your brain to stop relying on one eye, potentially worsening the problem.
Optic neuritis/vision loss:
One of the most common visual issues that comes with MS is optic neuritis. In fact, 50% of people with MS will eventually suffer with optic neuritis. Symptoms of the condition can include:
- Pain when moving your eyes
- Hole in central vision
- Blurred vision
- Dimmed colour vision
- Temporary loss of vision
- Reduced peripheral vision
Optic neuritis occurs when your immune system attacks the fatty coating which protects your optic nerve. This is an effect of MS, although experts aren’t entirely sure why, and it prevents your optic nerve from sending the correct signals to your brain. Optic neuritis typically occurs in one eye at a time and can last for anywhere from 4-12 weeks. In rare cases, the symptoms can take up to a year to disappear but a very small number of patients don’t ever fully regain their sight.
In terms of treating optic neuritis, IV steroids can be prescribed for the first episode of optic neuritis but low-dose oral steroids used over a long period can actually increase the chance of optic neuritis recurring. Your doctor may also prescribe vitamin B12 as it has been found that a lack of it can also bring on optic neuritis.
Finally, if you suffer from optic neuritis, it is important to be aware that hot environments can trigger an episode. Examples of this might be a hot shower, fever or intense exercise. You should be aware of how these settings or events could affect your vision and avoid them where possible, if you have MS and have already noticed changes to your eyesight.
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