Nystagmus: Infantile and Acquired Types, Causes and Management

Nystagmus is a condition in which the eyes make repetitive, involuntary movements, usually from side to side but sometimes up and down or in a circular pattern. The movements can be fast or slow, constant or intermittent, and they usually reduce the sharpness of vision because the eyes cannot hold steady on what the person is looking at. People with nystagmus that began in infancy often do not see the world moving; their brain has adapted. When nystagmus appears in adulthood, however, it often causes a disturbing sensation that the world is jumping or swaying, called oscillopsia.

Nystagmus is not a single disease but a sign that the systems controlling eye position are not working normally. It can be present from early childhood or develop later because of problems in the brain, the inner ear, medicines or other conditions. This guide explains the main types, their causes, the concept of the null point, how nystagmus is assessed and what can be done to help.

How eye movements are controlled

Keeping the eyes steady is surprisingly complicated. The brain combines information from the eyes, the balance organs in the inner ear (the vestibular system) and the neck to make constant tiny corrections. Several brain areas, including the brainstem and the cerebellum, act like a control system that holds the eyes on target, even when the head moves. Nystagmus arises when part of this control system is disrupted or has not developed normally, so the eyes drift and are repeatedly pulled back. Our guide on how vision works explains how the eyes and brain cooperate.

Describing the movements

Doctors describe nystagmus by:

• Waveform: jerk nystagmus has a slow drift in one direction and a quick corrective movement back; pendular nystagmus moves back and forth at equal speeds, like a pendulum.
• Direction: horizontal, vertical (upbeat or downbeat), torsional (rotatory) or mixed.
• Amplitude and frequency: how large and how fast the movements are.
• Conditions that change it: gaze direction, focusing on near objects, covering one eye, fatigue or stress.

Infantile nystagmus

Infantile nystagmus, sometimes still called congenital nystagmus, usually becomes noticeable between about 6 weeks and 6 months of age. Parents often notice the eyes wobbling or shaking. Estimates suggest it affects roughly 1 in 1,000 to 2,000 people, though figures vary.

It falls into two broad groups:

• Nystagmus associated with an eye or visual pathway condition (sometimes called sensory nystagmus). Poor vision early in life prevents the eye-position control system from developing normally. Causes include albinism, congenital cataract, optic nerve hypoplasia, aniridia, Leber congenital amaurosis, achromatopsia, congenital stationary night blindness and other retinal dystrophies.
• Idiopathic infantile nystagmus, where the eyes and brain are otherwise structurally normal. It is often inherited, for example through changes in the FRMD7 gene, which is X-linked and therefore more common in boys.

Infantile nystagmus is usually horizontal and remains horizontal even when looking up or down. It often lessens when focusing on near objects (convergence), which is why many children hold books and screens close. It may be worse with stress, tiredness or illness. Most people with infantile nystagmus do not experience oscillopsia.

Spasmus nutans and latent nystagmus

Spasmus nutans is a rare condition of infancy combining small, fast, often asymmetric nystagmus with head nodding and a head tilt. It usually resolves by early childhood, but because similar signs can rarely be caused by tumours of the visual pathway, children need careful assessment and sometimes brain imaging.

Latent (fusion maldevelopment) nystagmus appears or worsens when one eye is covered and is associated with infantile strabismus. It is one reason eye doctors are careful about how they test vision in children with squint. See our guide to strabismus and amblyopia.

Acquired nystagmus

Nystagmus that begins after infancy has many possible causes. Some are temporary and harmless; others need urgent attention.

Specific patterns can point to particular locations. For example, downbeat nystagmus is often associated with problems in the cerebellum or at the junction of the brain and spinal cord, and nystagmus that changes direction depending on where the person looks suggests a central cause. These patterns are interpreted by neuro-ophthalmologists and neurologists.

Physiological nystagmus

Some nystagmus is entirely normal. Watching a moving train produces optokinetic nystagmus, and spinning around produces nystagmus as the inner ear fluid settles. A few beats of nystagmus at the extremes of gaze are also common in healthy people.

Symptoms and effects on daily life

• Reduced visual acuity: the constant movement blurs the image. Many people with infantile nystagmus have moderately reduced vision, but some meet driving standards.
• Head posture: turning or tilting the head to use the null point.
• Oscillopsia: the world appears to move, mainly in acquired nystagmus.
• Slower visual processing: it may take longer to locate and recognise objects, faces or text, especially when tired or stressed.
• Balance and vertigo in inner-ear or central causes.
• Light sensitivity in conditions such as albinism and achromatopsia.

Nystagmus is a visible condition, and people often report frustration when others misinterpret eye movements or head posture. Explaining the condition to teachers, colleagues and friends helps.

The null point

Many people with nystagmus have a direction of gaze in which the movements are smallest and vision is sharpest. This is called the null point or null zone. If the null point is to one side, the person naturally turns their head the other way so their eyes are in that position when looking straight ahead. A child who always watches television with the head turned is often using a null point, not being careless.

Understanding the null point is practical:

• Positioning a desk, screen or seat in class so the person can use their null point comfortably improves reading and reduces strain.
• Many people also see better when focusing on near objects, called convergence damping.
• Surgeons can move the null point towards the straight-ahead position in selected cases, reducing the need for an abnormal head posture.

Diagnosis

Assessment usually involves an ophthalmologist, often a paediatric or neuro-ophthalmologist. It includes:

• A detailed history: age at onset, family history, symptoms such as vertigo or oscillopsia, medicines and general health.
• Observation of the eye movements in different directions of gaze, at distance and near.
• Visual acuity, refraction and examination of the front of the eye and the retina.
• Eye movement recordings in some centres.
• Electrodiagnostic tests such as electroretinography to detect retinal disease.
• Optical coherence tomography (OCT), which can reveal signs of albinism or foveal underdevelopment.
• Genetic testing in some infantile cases.
• Brain imaging (MRI) when there are neurological concerns or for acquired nystagmus.

Our guide on eye examinations explains many of these tests.

Management and treatment

There is no single cure for nystagmus, but a range of approaches can improve vision and quality of life. Treatment of acquired nystagmus focuses first on the underlying cause.

Optical correction

Correcting any refractive error with glasses is one of the most effective steps. Contact lenses can be particularly helpful because they move with the eyes and give clearer vision through the optical centre; some people find they also dampen the movements slightly. Tinted lenses can help with light sensitivity in conditions like albinism. Prisms in glasses can shift the null point or induce convergence to reduce nystagmus in selected cases.

Low-vision support

Low-vision aids, such as magnifiers, large print, high-contrast materials, tablets with zoom and accessibility features, and good lighting, help many people. Educational support and reasonable adjustments at school and work make a big difference. See our guide to low vision and visual impairment.

Medicines

For some forms of acquired nystagmus and, in some studies, infantile nystagmus, certain medicines acting on the nervous system have been shown to reduce eye movements and improve vision or oscillopsia. Small randomised trials have shown benefit for drugs such as memantine and gabapentin in some patients, but effects vary and side effects are common. These are prescribed by specialists; dosing is decided individually.

Surgery

Eye muscle surgery can be used to:

• Move the null point to the straight-ahead position and correct an abnormal head turn (the Anderson-Kestenbaum procedure and its variations).
• Reduce the intensity of nystagmus in some patients, for example by detaching and reattaching the horizontal eye muscles (tenotomy) or weakening several muscles.
• Treat associated strabismus.

Surgery does not cure nystagmus but can improve head posture, appearance and sometimes visual function. Botulinum toxin injections are occasionally used for disabling acquired nystagmus, though effects are temporary.

Driving, education and careers

Some people with infantile nystagmus meet the visual standards for driving, while many do not. Rules differ by country and are based on measured acuity and visual fields, so an eye specialist's assessment is essential. In education, children with nystagmus benefit from enlarged materials, extra time, seating near the front at their preferred angle, and digital devices that allow zoom. Many adults with nystagmus work in a wide range of careers with appropriate adjustments; see eye care by profession.

When to see a doctor

Parents should arrange an eye assessment if they notice their baby's eyes wobbling or shaking, a persistent head turn or tilt, poor visual attention, or a white pupil reflex. Adults with nystagmus since childhood should have regular eye examinations and seek review if their vision changes.