What is nystagmus?
Nystagmus, or ‘dancing eyes’, is the involuntary movement of the eyes. It usually looks like the eyes are constantly moving, either side to side, up and down, in a circle or a combination of all three. There are a few ways that this can affect the eyes and vision, depending on its underlying cause.
Types of nystagmus
There are two main types of nystagmus: congenital and acquired.
- Congenital nystagmus – also known as infantile nystagmus, this develops very early in childhood, typically in the first few months after they’re born. This usually happens when the part of the brain that controls eye movement doesn’t develop properly.
- Acquired nystagmus – this type develops later in life, usually in adults. This can happen as a result of damage to the area in the brain responsible for eye movement.
Symptoms of nystagmus
Symptoms of nystagmus can vary from person to person, depending on the type they have and its underlying cause.
Some people will only have very slight eye movement that isn’t always as obvious to spot and doesn’t affect their vision. While others will find that their vision is reduced, or that depth perception is trickier.
People with acquired nystagmus can sometimes experience what’s known as oscillopsia, which is the feeling that the environment around you is moving or wiggling. This can make you feel quite sick or affect your balance.
Nystagmus eye movements can be grouped into three different types:
Jerk nystagmus
This describes a slow movement of the eye in one direction, and then multiple and repeated quick jerk movements in the opposite direction.
Pendular nystagmus
The eye movement for this type is more like a pendulum moving back and forth.
Mixed nystagmus
This is a mixture of jerk and pendular nystagmus. Looking ahead the eyes move like a pendulum, but then jerk when looking to the side.
What causes nystagmus?
Nystagmus is usually caused when the parts of the brain that control eye movement don’t develop properly or become damaged. Sometimes the cause of nystagmus isn’t clear, which is known as idiopathic nystagmus.
Congenital nystagmus
This type of nystagmus is caused by a problem with the development of the eye or area of the brain that controls eye movement in small children. But sometimes there isn’t a clear reason why children develop nystagmus. Certain eye conditions people are born with can also be associated with nystagmus, including congenital cataracts, ocular albinism, and conditions that affect the retina or optic nerve.
Acquired nystagmus
In later life, acquired nystagmus is usually the result of damage to the parts of the brain responsible for eye movement. This damage can happen due to a head injury or conditions like strokes, multiple sclerosis or brain tumours. In rare cases, acquired nystagmus can be an effect of certain medications or alcohol.
Diagnosing nystagmus
It’s usually quite easy to pick up nystagmus in a baby’s first few weeks or months, after which a detailed examination of the eye will usually be needed to check for any underlying eye conditions that may be causing it and to assess how well they can see.
As acquired nystagmus can show the early signs of more serious conditions, adults will usually be referred to an ophthalmologist (eye specialist) or neurologist (brain and nervous system specialist) for further tests in order to diagnose its underlying cause.
Nystagmus treatment
There’s no cure for nystagmus at the moment, but some of its underlying conditions can often be treated. It’s mostly about learning to cope with its effects.
Glasses and contact lenses
Some people with nystagmus often experience reduced vision, which can be treated with glasses or contact lenses. Many people find that contact lenses are more helpful for nystagmus, as they move with your eyes, so you’re always getting the best vision. Whereas glasses require you to look through the middle of the lenses for clear vision, which isn’t always possible with certain nystagmus eye movements.
Surgery
Some children find that holding their head in a certain position, where the nystagmus is minimal, helps them to see better, which is known as a ‘null zone’. Surgery can sometimes be an option to change the position of the muscles that move the eye, reducing the need to move the head as much to get to the null zone.
Medication
Some cases of acquired nystagmus might benefit from certain medications to help control eye movements and reduce the effects of oscillopsia (the feeling that the environment around you is constantly moving).
Extra tips for children
Large print books can be useful for children with nystagmus when they’re learning to read. Having a chat with your child’s teachers is important to find what can work best, including extra time in tests to read the questions or sitting in a particular place in the classroom. Once diagnosed, children might benefit from a referral to a Visual Impairment Team, who can provide extra support at home, nursery and school.
If you ever have any concerns about your vision or eye health, get in touch with your local store to book an eye test. You can find more information, advice and support around nystagmus at Nystagmus Network.
