Visual symptoms are common amongst people with multiple sclerosis (MS).
There are three main visual symptoms in MS – optic neuritis, nystagmus and diplopia (double vision). Some people also experience temporary blurring of vision, temporary loss of vision, blind spots, pain with eye movement and blind spots.
Visual problems are often the first symptoms associated with MS (1).
‘Accept that it can take time to focus. Just sit down, relax, and wait. A cold flannel across the eyes helps me’
‘I keep things in their place so I know where they are. Wear sunglasses, and have large-print letters sent’
Optic neuritis is a common symptom in MS. It is caused by inflammation or demyelination to the optic nerve at the back of the eye, which transmits the signals from the visual image from the eye to the brain (1).
Optic neuritis causes a disturbance in vision – sometimes blurring, and often a reduction in colour vision, particularly for the colour red. Optic neuritis can also cause a headache, or a pain behind the eye when the eye moves (2).
Visual flashing sensations can be present and over half of those affected by optic neuritis will experience Uhthoff’s sign – in which symptoms worsen with heat or exhaustion. (3)
Optic neuritis is a variable condition where vision can be moderately to severely affected. It usually occurs in one eye but can occur in both eyes at the same time (2).
Optic neuritis starts suddenly and progresses for a few weeks before recovery happens spontaneously. Treatment with steroids may be advised by your MS nurse to help reduce inflammation and hopefully help speed up recovery (2).
If the optic nerve is damaged by demyelination a permanent loss of visual acuity (acuteness or clearness of vision), may be experienced.
‘I use magnifying glasses for close up work and always try to have a magnifying glass in my pocket if I’m out in order to read menus and so on.’
Nystagmus is a condition in which the eyes move involuntarily. The movement is usually horizontal, but it can also be vertical or rotary. In almost all cases, both eyes move together. There are two main types of nystagmus, one which appears in the first months of life which is called congenital nystagmus and another which develops later in life which is usually called acquired nystagmus (4).
Acquired nystagmus is most common in people with MS and although they may be initially unaware of these involuntary movements, they may notice movement themselves in a mirror or it could be observed by others. Nystagmus will be diagnosed by an ophthalmologist who will examine the inside of your eyes and test your vision. Diagnosing acquired nystagmus may also require a referral to a neurologist (5).
Although acquired nystagmus is quite a common symptom, treatment of this condition is limited at present. Drug therapy with gabapentin or memantine may help (6). Botulinum toxin injections have also been shown to help some people with the acquired form of nystagmus associated with MS (7).
‘Get your eyes checked by an optician and speak to your MS team’
Diplopia, or double vision, can be a very early symptom of MS. It is caused when the pair of muscles that control a particular eye movement are weakened. The muscles then become uncoordinated, and this disturbs the vision by producing images in double. It may also cause loss of balance because spatial orientation, that ability of a person to correctly determine his/her body position in space, is disturbed. Double vision is usually temporary. It can occur through fatigue or over-use of the eyes. For example, too much time spent on a computer or reading for a long time. Resting the eyes periodically throughout the day can be beneficial (8).
If you experience double vision, talk to your GP or MS nurse about a referral to an ophthalmologist.
‘You can get prism glasses for double vision. Rest your eyes from screens when necessary’
Nutrition, supplements and eye health
The key vitamins for eye health are the antioxidants – vitamins A, C and E, lutein and zeaxanthin. These support eye health and are all found in fruits and vegetables. Lutein is found in mango, yellow peppers and green leafy vegetables such as kale, chard, broccoli and cavolo nero. Zeaxanthin is found in orange sweet peppers, citrus fruits such as oranges and tangerines, broccoli, corn, spinach and eggs. These types of food also provide vitamins A, C and E. If you have a healthy diet with a good balance of fruit and vegetables, then you will get all the vitamins you need from your food, although you can choose to supplement these vitamins (9).
‘I tolerated it until diagnosis and then ate punnets and punnets of blueberries to reduce the inflammation. Now very rare occasional relapses with slight blurring’
Vitamin D is important for a healthy immune system, brain development and function and the cardiovascular system (heart and blood vessels). Vitamin D helps the body to absorb calcium and phosphorus – the building blocks for strong bones.
A study looking at the effect of vitamin D in recovery from acute episodes of optic neuritis in people with MS found a link between the severity of optic neuritis and vitamin D levels. People with higher levels of vitamin D had less severe episodes of optic neuritis. However, there was no association with high vitamin D levels and a faster recovery from optic neuritis (10).
In the UK the NHS recommends people should have their eyes tested approximately every two years. This ensures that your eye health is checked regularly and any issues that require attention can be addressed without delay. Some people may be eligible for free NHS eye and sight tests (11).
‘The one thing that kept me sane was using audio books (tapes) from the library. I could put them on, lie in bed and doze or sleep. Particular narrators are very good for lulling you to sleep!’
MS-UK Choices booklets – MS symptoms and Vitamin D
The effects of gabapentin and memantine in acquired and congenital nystagmus: a retrospective study. T Shery, F A Proudlock, N Sarvananthan, R J McLean, and I Gottlob. Accessed August 2021. www.ncbi.nlm.nih.gov/pmc/articles/PMC1857134
Nystagmus Network. Treating Nystagmus. Accessed August 2021. nystagmusnetwork.org/information/treatment
National Center for Biotechnology Information (NCBI). Factors associated with recovery from acute optic neuritis in patients with multiple sclerosis. Published 17 June 2014. Accessed August 2021. www.ncbi.nlm.nih.gov/pubmed/24850491