Nystagmus is a condition of uncontrolled eye movement. If you have nystagmus, your eyes move or “wobble” constantly. This can be in a side to side, an up and down, or a circular motion, or a combination of these. This uncontrolled movement can affect how clearly you can see. Most people with nystagmus have reduced vision.

Nystagmus is caused by a problem with the way the eye sends messages back to the brain or how parts of the brain which deal with eye movement make sense of the information.

What are the different types of nystagmus?

There are two main types of nystagmus:

• infantile or congenital nystagmus which appears in the first few months of life, and
• acquired nystagmus, which develops later in life.

Infantile or congenital nystagmus

Infantile or congenital nystagmus is also sometimes known as “early onset nystagmus” or “infantile nystagmus syndrome” (INS). It is usually diagnosed in very young children, soon after they’re born or sometimes in the first few months of their life. This type of nystagmus can be associated with a problem with the eyes themselves or with a problem with the parts of the brain which control eye movements. But sometimes children develop nystagmus without any of these problems.

Some eye conditions which a baby is born with can be associated with nystagmus, including:

• congenital cataracts
• ocular albinism
• retinal dystrophies, such as cone dystrophy, congenital stationary night blindness, or Leber congenital amaurosis

However, many children with nystagmus don’t have any problem with their eye, brain or health. When a cause for the nystagmus can’t be found, it is called “idiopathic infantile nystagmus” or “idiopathic nystagmus syndrome”. Some of these children may have a faulty gene known to cause nystagmus.

Acquired nystagmus

Nystagmus that develops later, mostly in adults, is called “acquired nystagmus”. Anything that damages the parts of the brain that control eye movements can result in acquired nystagmus.

Acquired nystagmus is usually a sign of another underlying condition such as stroke, multiple sclerosis, brain tumour, head injury or the effects of a drug.

What are the effects of nystagmus on sight?

If you have nystagmus, your eyes are always moving, although it may not always be obvious to you or others. The way that nystagmus affects vision varies from person to person; however, it doesn’t lead to total loss of sight.

Infantile nystagmus

How your vision is affected if you have infantile nystagmus varies a lot and can often depend on the underlying cause of your nystagmus. Some people may be able to read most sizes of print without help, while others may have a significantly reduced level of vision. Most people with nystagmus have some useful vision and normally nystagmus doesn’t get worse with age.

Your vision can vary in quality when you have nystagmus, depending on which direction you’re looking in or whether you’re looking at something far away or close.

Your vision can also vary depending on how you’re feeling. The more stressful or tiring you find a situation, the worse your vision can become. Your vision may also become worse when you’re feeling unwell, or if you’re anxious or upset.

Having nystagmus may mean that you need longer to see or read things. The constant movement of your eyes means that you have less time to focus on what is in front of you, for example printed text.

The effects of nystagmus may improve when your head is held in a particular position, which can help you to see things better. This is known as the “null zone”. This is often the direction of your gaze where your eye movements are slowest and most stable. Slowing or making eye movements more stable may mean your vision becomes clearer. Children with infantile nystagmus often find their null zone naturally. Parents or teachers may notice that a child tilts their head to one side, or looks at things sideways. Some people with nystagmus also find that nodding their head helps to improve their vision.

People with nystagmus may find they have poor depth perception and so may find it difficult to judge distances and height.

Acquired nystagmus

If you develop nystagmus later in life, you may experience a constant awareness of the world moving around you, or in front of you. This is known as oscillopsia.

As the nystagmus is new, your brain has not adapted to the unexpected eye movements and so it sees the world moving. This is very disabling and can make things very difficult to see, as well as sometimes making you feel sick and dizzy.

Depending on what has caused your acquired nystagmus, it may be a short-term condition that might get better. However, some people have the condition for the long term which can cause problems with how well they can see as well as being disorientating.

How can nystagmus be managed?

There is currently no cure for nystagmus. Having nystagmus can cause reduced vision but there are things which can help manage the condition and make the most of your sight.

• Glasses and contact lenses will ensure that you, or your child, have the best vision possible. They can’t correct nystagmus but can correct for any refractive error you may have. In young children with infantile nystagmus, treatment with glasses is important to help their vision develop as fully as possible.
• A low vision assessment will look at ways to help people make the most of their vision. This may mean making things bigger, using brighter lighting, or using colour or contrast to make things easier to see. The assessment gives people a chance to discuss any practical problems they are having with their vision with a low vision specialist. The specialist can explore things like magnifiers, lighting, colour contrast and other adaptations that may help, such as tinted glasses which may be useful to control glare.

There are also some other options which can sometimes help to manage nystagmus. These options don’t work for everyone as their suitability varies from person to person. The options are:

• Surgery can be used to change the position of the muscles that move the eye. The surgery can’t correct the nystagmus but can be helpful in reducing the amount a person needs to turn their head to get to their null zone, making it more comfortable to keep their head in the best position. It doesn’t work for everyone and it usually isn’t considered until a child is older and when the null zone is more stable.
• Medication and drugs may be used in some specific cases of acquired nystagmus, for example if the nystagmus is caused by multiple sclerosis. Drugs can sometimes help control eye movements and reduce the symptoms of oscillopsia. However, for many people the side effects of these drugs may outweigh the benefit they get.
• Botulinum toxin (Botox) injections into the eye muscles may occasionally be used to help some people who have acquired nystagmus that is caused by a neurological problem, such as multiple sclerosis. Botox weakens the eye muscles and helps to slow down the movements. The effects are only temporary but can sometimes help to reduce the symptoms of oscillopsia in the short term. However, Botox can weaken all eye movements and not just the eye movements relating to the nystagmus, so this can cause its own problems which limits the usefulness of this treatment.

You may hear of research into other management therapies such as acupuncture or biofeedback, which aims to reduce nystagmus through audio signals. However, it’s uncertain whether any of these therapies work and more research is needed.

Coping

It can seem overwhelming at first if you or your child have just been diagnosed with nystagmus. Although nystagmus can cause problems with your sight, with the right support at the right time, most people can lead full and independent lives.

We’re here to support you every step of the way, and to answer any questions you may have – just get in touch with our Sight Loss Advice Service. You might also find the information on our children, young people and families pages helpful.

Depending on how much of a person’s sight is affected by nystagmus, they may be eligible to be registered as sight impaired (partially sighted) or severely sight impaired (blind).