What is visual tracking?
Visual tracking refers to the ability to follow an object with your eyes. It is a process in which the brain coordinates eye muscle movements so that you can:
- Focus on a stationary object
- Keep moving objects in the center of your sight
- Make quick adjustments in your point of gaze (what you look at)
Visual tracking skills involve three main types of eye movement:
- Fixation – Maintaining your gaze on a non-moving object
- Smooth pursuit – Following a moving object
- Saccades – Rapidly shifting your gaze between two or more objects
These skills develop very early in life, typically in the first few months. The ability to visually track continues to improve through adolescence then eventually declines with age.
Visual tracking skills vs. eye teaming skills
Visual tracking is sometimes confused with eye teaming. They are both related to eye movement and are important to the visual system. However, they involve different functions.
Visual tracking skills allow you to look at and follow an object with your eyes. Eye teaming (also known as binocular vision) allows your eyes to work together to view an object as a single image.
It’s possible to have both eye teaming and visual tracking issues at the same time. Even people with normal visual acuity can have eye tracking and teaming problems.
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Importance of visual tracking
One of the most important aspects of visual tracking is the ability to move the eyes without moving the head. This is key for activities such as:
- Reading – Efficient readers use controlled eye movements to follow text without moving their heads.
- Sports – Athletes must be able to follow fast-moving objects with minimal head movement. High-level tracking skills also influence hand-eye coordination, reaction time and balance in sports.
The ability to visually track an object is also important for a wide range of other functions and activities, including:
- Hand-eye coordination
- Cognitive development
- Attention
- Behavior
- Academic performance
- Everyday tasks (such as driving and navigating your surroundings)
Because these skills are so significant, identifying eye tracking problems early is essential.
Attention and visual tracking
Tracking skills are highly dependent on attention. As a result, children with attention deficit hyperactivity disorder (ADHD) are more likely to experience visual tracking issues. These may contribute to impulsivity, learning difficulties and behavioral problems.
Recent research shows that improving visual tracking skills in children with ADHD can lead to:
- Better eye movement control
- Improved cognitive function and coping behavior
- Decreased hyperactivity and impulsivity
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Recognizing a visual tracking disorder
Visual tracking disorders are also called oculomotor dysfunctions (OMDs). These conditions can affect people of all ages.
Symptoms of OMDs vary but can include:
- Losing place or skipping lines while reading
- Feeling eye fatigue after short periods of reading
- Miscalling words
- Using a finger to follow a line while reading
- Moving the head excessively when reading
- Inability to copy from the board
- Attention or behavioral issues
- Poor reading comprehension
- Poor handwriting
- Poor hand-eye coordination
OMD symptoms may be subtle in certain cases and can overlap with other conditions. Therefore, these disorders may be misdiagnosed or go undiagnosed.
Causes of a visual tracking disorder
Various conditions and other factors can lead to the development of visual tracking disorders. Some of the more common causes include:
Developmental delays
The ability to visually track an object is controlled by the brain, which is part of the central nervous system (CNS). Saccadic eye movements play a large role in a child’s development, especially in skills like reading and hand-eye coordination. These skills also require the ability to maintain attention and plan movement.
Poor saccadic eye movements may contribute to reading and learning disabilities in children. Visual tracking problems are also observed in some children with autism spectrum disorder, dyslexia and other developmental conditions.
Traumatic brain injury (TBI)
TBI is a condition that commonly causes eye tracking issues. It can make certain activities more difficult to do, such as reading, scrolling on a computer screen and driving. Some TBI patients experience fatigue, which could also contribute to visual tracking problems.
Stroke
The majority of people who experience a stroke have oculomotor dysfunction. They may have trouble with saccades and other eye movements, which could lead to difficulties with:
- Reading
- Hand-eye coordination
- Balance and depth perception
- Navigating their environment
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Central nervous system disorders
CNS disorders can also cause oculomotor dysfunction. Some of these disorders include:
- Multiple sclerosis
- Parkinson’s disease
- Alzheimer’s disease
- Huntington’s disease
Eye movement control is very complex and involves many areas of the brain. Variations in eye movement disorders help doctors pinpoint what area of the brain is affected. This can help determine if a CNS disease is contributing to OMD.
Other causes of oculomotor dysfunction
Additional conditions can contribute to visual tracking disorders, including:
- Brain tumors
- Migraine headaches
- Diseases that affect the blood vessels (such as hypertension and diabetes)
- Weak, bulging blood vessels in the brain (aneurysm)
- Certain infections (such as Lyme disease and HIV)
Visual tracking testing and diagnosis
Various tests are used to help identify and diagnose visual tracking disorders. These range from simple paper tests to advanced computer-based systems, including:
Developmental eye movement (DEM) test
The DEM test involves thetimed reading of numbers as the eyes track across a printed page. During this test, participants read columns of numbers vertically and rows horizontally. Performance on the DEM test provides details about factors such as:
- Reading speed and proficiency
- Visual processing rate
The DEM test is traditionally a manual, paper-based test but a digital version is also available.
King-Devick (K-D) test
The K-D visual tracking test involves the timed reading of rows of single-digit numbers as the eyes track across a printed page. The test assesses factors such as:
- Attention and focus
- Language skills
- Reading speed and proficiency
- Visual processing rate
While traditionally performed on paper, it can also be administered through a digital tablet.
RightEye Sensorimotor System
The RightEye Sensorimotor System is a computer-based test that records and analyzes eye movements. It uses an eye “tracker” that measures factors such as:
- Various aspects of eye movement
- Brain processing speed
- Reaction times
ReadAlyzer
The ReadAlyzer is a computer-based test that measures how a person’s eyes move and focus while reading. It uses a pair of safety goggles equipped with infrared sensors. These sensors detect reflections from the cornea (the clear outer layer of the eye), which helps track eye movement.
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Activities and exercises to improve visual tracking
Visual tracking disorders are typically treated with a variety of vision therapy techniques. These techniques involve visual tracking exercises and activities designed to improve fixation, pursuit and saccadic eye movements.
Examples of visual tracking activities include:
Gross motor activities
These involve physical exercises like:
- Throwing or catching a ball
- Playing tennis or badminton
- Flashlight tag
Paper-pencil tasks
These might include activities such as:
- Solvingmazes and word search puzzles
- Connecting the dots
- Working on crosswords
Computer-based training programs
Various computer programs are used for oculomotor training. Some of these include:
- RightEye
- ReadAlyzer
- Vivid Vision
The goal of visual tracking exercises and activities is to improve visual skills, function and efficiency.
When to see a doctor
Visual tracking skills play a large role in many daily activities. However, tracking disorders can often go unnoticed. Symptoms can vary but may include losing your place when reading or difficulty following a moving object. Children may avoid activities that require ongoing focus, while adults might struggle with driving and other everyday tasks.
If you or your child experience any visual tracking issues, it’s important to consult your eye doctor. They can determine if an oculomotor problem exists and develop a treatment plan to improve this part of your vision.
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