Nystagmus is a condition in which the eyes make rapid, repetitive, and involuntary movements.  Sometimes, it is referred to as “dancing eyes”. It affects one or, more commonly, both eyes and impacts the person’s vision and balance. 

Nystagmus can be congenital (present at birth or shortly after) or acquired (developed anytime after 6 months of birth) and affects up to 24 in 10,000 individuals.

Congenital nystagmus is due to developmental abnormalities. However, acquired nystagmus can be caused by several medical or neurological factors. It is hence important to diagnose the condition and uncover any underlying issues.¹ 

Here, we will discuss the four types of nystagmus based on the directions of the eye movements.

What happens in nystagmus

Simply put, our eyes are like cameras. They are constantly adjusting to keep everything in focus,² whether it’s reading, watching something moving, or looking at distant objects. Normally, the brain, inner ear, and muscles around the eyes work together to keep the eyes steady or moving smoothly.

In nystagmus,¹ this coordination is broken. It’s like holding a camera with shaky hands. The eyes begin to move on their own, usually in a repetitive pattern: side to side, up and down, in circles, or a combination. These movements can be slow or fast, steady, or jerky.

It might seem unusual, but nystagmus doesn’t always mean something serious is wrong. Some people are born with it and adapt well, while others develop it due to temporary conditions like ear infections or medication effects. With proper care, many can lead completely normal lives.

Types of nystagmus based on the direction of eye movement

There are 4 types:

• Horizontal nystagmus: side-to-side eye movements
• Vertical nystagmus: up-and-down eye movements
• Rotary (torsional) nystagmus: rotational or circular eye movements
• Mixed nystagmus: a combination of two or more of the above movement types

Let us look at each more closely.

Horizontal nystagmus

Horizontal nystagmus, one of the most common types, is characterised by involuntary movements of the eyes.    

• Congenital³ or developmental issues: like albinism, underdeveloped optic nerves or cataracts.
• Inner ear problems: Conditions such as benign paroxysmal positional vertigo (BPPV) or vestibular neuritis can disturb balance and cause horizontal nystagmus  
• Brain issues: Stroke or multiple sclerosis can affect the nerves that control eye movements  
• Alcohol or medication: Consuming excess alcohol or medications can temporarily cause horizontal nystagmus.  

How does it affect people?     

People with horizontal nystagmus may experience dizziness and an illusion of objects moving back and forth, even when they are still, making activities like reading or driving difficult.  

Diagnosis and treatment

Doctors use tests like videonystagmography (VNG) to measure eye movements and determine the area of difficulty. Treatment depends on the cause:

•  If it’s due to an inner ear problem, exercises can help to learn to balance.
•  Medications might be prescribed for neurological causes.
•  Avoiding triggers like alcohol can also reduce symptoms.

Vertical nystagmus

Vertical nystagmus involves up-and-down eye movements and is less common than horizontal nystagmus.  

Causes of vertical nystagmus

Vertical nystagmus is often related to problems in the brain, like:

• Cerebellar dysfunction:⁴ The cerebellum is a part of the brain that controls movement and balance. Issues here can lead to vertical nystagmus⁴
• Drug toxicity: certain medications, like lithium or anti-seizure drugs, can cause this type of eye movement
• Nutritional deficiencies: lack of vitamins like thiamine (vitamin B1) may result in conditions like Wernicke’s encephalopathy, which causes vertical nystagmus⁵

How does it affect people?

People with vertical nystagmus experience visual instability, making it is hard to focus on objects above or below their line of sight. They might also feel giddy or disoriented.

Diagnosis and treatment     

Doctors use advanced tools like video-oculography (VOG) to analyse vertical eye movements in detail. Treatment includes:

• Managing underlying causes, such as nutritional deficiencies
• Medications (like gabapentin) can reduce symptoms caused by brain-related issues.

Rotary (torsional) nystagmus

Rotary nystagmus involves circular eye movements around an axis, giving it a spinning appearance.

Causes of rotary nystagmus   

Rotary nystagmus is often caused by disorders in the semicircular canals in the inner ear, which otherwise detect rotational head movements. Sometimes, it could be brain-related, too.

Common causes include:

•  Labyrinthitis: inflammation of the inner ear
• Vestibular neuritis: viral infection affecting balance-related nerves
• Brainstem injuries: damage to areas controlling rotational eye movement.

How does it affect people?     

People with rotary nystagmus often experience vertigo – a spinning sensation – and difficulty maintaining visual stability during head rotations.

Diagnosis and treatment     

Tests like electronystagmography (ENG) are used to differentiate between inner ear and brain-related causes of rotary nystagmus.

•  Vestibular rehabilitation exercises for inner ear issues
•  Medications like meclizine can help manage vertigo symptoms
  

Mixed nystagmus

Mixed nystagmus presents with two or more directions of eye movements.

Causes of mixed nystagmus

The mixed eye movements are caused by multiple parts of the nervous system being affected at the same time:

•  Brainstem strokes: damage to multiple neural pathways controlling eye movement
• Congenital forms: infantile nystagmus syndrome (INS), which involves disrupted sensory input from birth
• Neurological diseases – conditions like multiple sclerosis or cerebellar atrophy

How does it affect people?    

Mixed nystagmus leads to unpredictable eye movement patterns that make routine tasks difficult, especially those requiring steady vision.

Diagnosis and treatment

Advanced imaging techniques like MRI can identify the central nervous system 

•  Corrective lenses with prisms help stabilise vision
• Minimally invasive Surgical interventions can relieve severe visual instability

Living with nystagmus 

Having nystagmus can be a challenge for day-to-day life. However, with the right support system and management, the quality of life of the people affected can be improved.

It is not always fully curable, but apart from medical treatment, the following ways can help reduce its impact on daily activities.

Adaptation strategies  

Adapting to nystagmus often involves making practical changes to accommodate visual instability.  

Use of aids 

Other than corrective eyeglasses or contact lenses, magnifiers and large-print reading materials can help individuals read more comfortably. These devices make tasks like reading easier. Digital devices, like mobile phones or tablets, with adjustable text sizes and screen magnification features, are also helpful.

 Environmental modifications

Creating a visually friendly environment—adequate lighting, minimising glare, or using curtains—prevents visual discomfort and improves clarity. Clearing up physical clutter also helps to see items more efficiently.

Support systems  

Support systems can play a big role in helping individuals cope with the emotional and practical problems of nystagmus.  

Joining support groups and sharing experiences, tips, and coping mechanisms can provide emotional comfort and create a sense of community. Online forums or local meetups are the resources for building connections among people with nystagmus.  

Summary

Nystagmus is a condition characterised by involuntary eye movements that can affect vision and balance. 

It is classified into four main types based on the direction of these movements: horizontal, vertical, rotary, and mixed. Each type has unique causes and symptoms—hence, these must be identified to have the most optimal management.

Medical help is imperative for diagnosis and treatment. Advanced diagnostic tools like MRI, VOG, VNG and ENG can reveal underlying causes, while personalised therapies will manage symptoms.

Regular monitoring by ophthalmologists or neurologists of nystagmus is advisable. They can then adjust treatments, recommend therapies, or provide further guidance.

Living with nystagmus requires patience, adaptability, and support. By taking corrective steps, using aids, and joining supportive communities, individuals with nystagmus can live an active and fulfilling lifestyle.

FAQs

Can nystagmus be prevented?

No, currently, nystagmus cannot be prevented. 

Should I wait before I seek medical help?

No, please seek medical help as soon as one notices anything wrong with the vision.

Is nystagmus curable?

It depends on the type of nystagmus. Some, mostly acquired cases, can be cured by treating the underlying cause. For others, mainly congenital cases, timely and specialised treatment can manage symptoms quite well.