Understanding Esophoria: Impact on Vision & Treatment Options

Learn about how Esophoria affects your vision, the difference between Esophoria and Esotropia and available treatment options. Our guide helps you make informed decisions about eye care.

Understanding Esophoria: Impact on Vision & Treatment Options Optometrist
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The American Optometric Association states that about 3-5% of the population experience some form of eye alignment disorder, which includes conditions like esophoria, esotropia, and other types of strabismus.

Esophoria is a condition where the eyes have a tendency to turn inward when they're not focused on an object. It's different from esotropia, where the eyes are actually misaligned. With esophoria, your eyes generally stay straight, but they drift inward when you're not focusing, like when you're daydreaming or tired.

Impact on Vision

Esophoria can have several effects on your vision and overall well-being, and it's important to understand how it may impact your daily life. 

Esophoria can also have different names or even become classified as different conditions depending on the distance that the esophoria is most noticeable.

  • Divergence insufficiency (esophoria that is worse at distance)
  • Intermittent esotropia (an esophoria that becomes present at all times)
  • Convergence excess (esophoria that is worse when looking at things close up)

Below are some of the ways this condition can affect vision in greater detail:

Visual Clarity and Stability

Esophoria often interferes with the ability to maintain clear, stable vision. Your eyes have to work extra hard to stay aligned, which can cause fluctuations in vision clarity. This could manifest as episodes where text seems to blur or become double momentarily, especially when reading or working on a computer for an extended period.

Frequent Refocusing

People with esophoria may find that they need to frequently refocus their eyes. For example, when shifting your gaze between your computer screen and a document, you might experience a brief moment of double vision or blur. This is because the eyes may momentarily drift inward before realigning.

Adaptation to Dim Light

Esophoria can become more pronounced in dim light conditions. When the light is low, it's harder for the eyes to find a point to focus on, and this can cause them to drift inward more frequently. This could affect activities like driving at night, where clear, stable vision is essential.

Visual Fatigue

The extra effort needed to maintain eye alignment often leads to quicker onset of visual fatigue. Tasks that require prolonged visual focus, such as reading, computer work, or even watching a movie, can become tiring much sooner than they would for someone without esophoria.

Reduced Visual Multi-Tasking

Esophoria can also affect your ability to switch attention between different visual tasks. If you're cooking, for example, you might find it difficult to quickly shift focus from chopping vegetables to watching a pot on the stove, leading to momentary blur or double vision.

Uneven Visual Performance

You might notice that the effects of esophoria are more pronounced at certain times, like when you're tired or stressed. This inconsistency can make it challenging to perform tasks that require good vision and concentration consistently well throughout the day.

Importance of a Functional or Developmental Eye Exam

If you're experiencing any of these issues, it's important to get a functional or developmental eye exam for a proper diagnosis and treatment plan. These exams are more thorough than a traditional eye exam and examine the full functioning of the visual system. Don't let these symptoms go unchecked. The sooner you address them, the less impact they'll have on your quality of life.

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Different Treatment Options for Esophoria

Managing esophoria effectively often requires a tailored approach that may include a combination of treatments. Let's dive into some of the primary options:

Eyeglasses & Prism Lenses

What They Are: Prescription eyeglasses are one of the most common treatments for esophoria. These could be single-vision lenses, bifocals or progressive lenses, or prism lenses.

How They Help: Glasses can help correct any associated refractive errors like nearsightedness or farsightedness, making it easier for your eyes to focus. Your eye doctor may recommend prism lenses, which can help correct minor eye misalignments by shifting the image slightly, allowing the eyes to work together more efficiently. Sometimes prism lenses are used in combination with vision therapy.

Vision Therapy

Vision therapy is a highly effective treatment option for improving how well your eyes work together, known as eye teaming or fusion. In esophoria, the primary goal of this therapy is to teach your eyes to align properly, focusing specifically on enhancing your ability to diverge your eyes outward.

How Vision Therapy Works for Esophoria

In vision therapy, you'll engage in specialized tasks and exercises designed to:

Identify Poor Eye Coordination: The first step is recognizing when your eyes are not working in sync.

Improve Convergence: This helps you focus on near objects by pulling your eyes inward.

Enhance Divergence: Conversely, this trains your eyes to focus on far objects by moving outward.

Switch Between Convergence and Divergence: Developing this skill makes it easier for you to adapt to different visual scenarios quickly.

Types of Exercises and Tools Used

You're likely to use a variety of tools and techniques, including:

  • Computer or virtual reality games that target specific visual skills.
  • Vectograms to help with depth perception.
  • Lens/prism flippers for quicker focus adjustments.
  • Loose lenses with varying powers to challenge your focusing ability.
  • Brock string to train binocular vision.

Why Professional Guidance Matters

Although at-home exercises like pencil push-ups may offer some benefits, active vision therapy supervised by an eye care provider generally leads to better outcomes. A vision therapy practitioner can tailor the treatment plan to fit your unique visual needs, providing more focused and effective therapy.

By working closely with a professional, you're more likely to improve both your convergence/divergence skills and your focal abilities, helping your eyes function more harmoniously.

Other Treatment Options

While eyeglasses and vision therapy are primary treatment methods, other approaches might be considered based on the severity of the condition and individual needs:

  • Pharmacological Treatments: Sometimes, eye drops or oral medications are prescribed to relax the eye muscles temporarily, although this is usually not a long-term solution.
  • Surgery: In severe cases where non-surgical treatments are ineffective, eye muscle surgery may be considered. This is typically a last resort and is more commonly used for more severe forms of strabismus like esotropia. In many situations surgery will be more successful in combination with vision therapy.

Proper diagnosis and ongoing monitoring are crucial for successful esophoria management. If you're experiencing symptoms, a functional or developmental eye exam can help identify the best treatment plan for your needs, often involving one or more of the options listed above.

Esophoria vs. Esotropia: Understanding the Difference

Esophoria vs. Esotropia: Understanding the Difference

Both esotropia and esophoria involve the tendency for the eyes to turn inward, but there are key differences in terms of when this happens, how it affects vision, and how it is managed. Understanding these differences is important for proper diagnosis and treatment.

When It Happens

Esophoria: Your eyes have a tendency to drift inward, but this usually happens when you're not focusing on an object or when you're tired or daydreaming. Most of the time, the eyes maintain proper alignment.

Esotropia: In this condition, one or both eyes are turned inward all the time or much of the time, even when you're focusing on an object. It's a constant misalignment and can be noticeable to others.

Effect on Vision

Esophoria: 

Esophoria can lead to many different symptoms including:

  • Depth perception might be affected, but generally not as severely as in esotropia.
  • General fatigue (especially after school, reading, or prolonged computer use)
  • Difficulty concentrating
  • Tired eyes
  • Eyestrain (Asthenopia)
  • Blurred vision
  • Double vision can also occur, but it's usually transient and happens when the eyes are tired or when shifting focus. 
  • Headache and migraines
  • Difficulty reading
  • Difficulty at night or in low light situations

Esotropia: Because the eye is actually misaligned, double vision is more common. Children with esotropia often develop a coping mechanism called suppression, where the brain ignores the image from the turned eye to avoid double vision. This can lead to Lazy eye (amblyopia) which may cause noticeable changes to eye alignment, poor depth perception, difficulty reading, and loss of binocular vision.

Management and Treatment

Esophoria: Management is often less invasive and may involve vision therapy exercises to strengthen eye muscles and techniques to improve eye alignment. Prescription eyewear can also be helpful.

Esotropia: Treatment usually involves more aggressive interventions like prescription eyeglasses with prisms, vision therapy, and in some cases, surgery to realign the eyes.

Visibility

Esophoria: The misalignment is usually not visible to others because it occurs when the eyes are at rest or unfocused.

Esotropia: The misalignment in esotropia is generally visible to others and can have social implications, especially for children.

How Common is Esophoria?

How Common is Esophoria?

Esophoria is a relatively common eye condition, although specific prevalence statistics can be hard to pinpoint.

For example, two different studies on 7th grade children showed dramatically different incidence of esophoria. 

Study on 2289 7th grade students in Sydney Australia showed a 10.4% incidence of esophoria.

https://iovs.arvojournals.org/article.aspx?articleid=2387513

Study on 2260 7th grade students in Henan Province, China showed a .61% incidence of esophoria

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7201350

Esophoria after concussions or head injury: estimated prevalence of 28% (https://www.reviewofoptometry.com/breakingnews/article/esophoria-prevalence-in-concussed-patients-revealed)

Given that esophoria is among the milder forms of eye alignment issues and can often go unnoticed unless symptoms flare up, it is believed to be more common than the more severe forms like esotropia. However, it's important to note that many people with esophoria may not even be aware that they have it, as symptoms can be subtle and might only become apparent during times of stress, fatigue, or intense concentration.

Is Esophoria Genetic?

Esophoria, like many other eye conditions, can have a genetic component. This means if you have family members with esophoria or other eye alignment issues like esotropia, you may be at a higher risk for developing the condition yourself. However, genetics is just one piece of the puzzle; it's not the sole determining factor.

Other Contributing Factors

Besides genetics, other factors can contribute to the development of esophoria:

Environmental Factors: Prolonged near work, such as reading or computer use, may exacerbate symptoms.

Physical Trauma: Injuries to the eye or surrounding areas can affect eye alignment.

Age: Eye alignment can change as you age, sometimes leading to esophoria in older adults.

Medical Conditions: Some neurological disorders or other systemic health issues could contribute to esophoria.

Conditions Associated with Esophoria

Conditions Associated with Esophoria

Esophoria can sometimes occur in isolation, but it may also be associated with other medical conditions or eye disorders. Here are some conditions that can be linked with esophoria:

Refractive Errors

How They Relate: Refractive errors like nearsightedness (myopia), farsightedness (hyperopia), and astigmatism can make it more challenging for the eyes to focus. This added effort can exacerbate the inward drift seen in esophoria.

Management: Corrective lenses or contact lenses often help in managing both the refractive error and the esophoria. In some cases, prism lenses may be prescribed.

Binocular Vision Disorders

How They Relate: Convergence insufficiency, for example, is a disorder where the eyes struggle to turn inward when focusing on near objects. This can make symptoms of esophoria worse.

Management: Vision therapy exercises aimed at improving binocular vision can be particularly helpful.

Neurological Conditions

How They Relate: In cases involving patients with a medically confirmed diagnosis of concussion, the prevalence of esophoria is notably higher. Approximately 30% of concussed patients were found to exhibit esophoria at near vision, indicating that nearly one in three such individuals experiences this eye alignment issue. Conditions like multiple sclerosis or traumatic brain injuries can impact the nervous system's control over eye muscles, making it more difficult to maintain proper eye alignment.

Management: Treatment often involves a multidisciplinary approach, including neurologists, to address the root issue.

Diabetes

How They Relate: Over time, diabetes can cause damage to blood vessels and nerves in the eyes, affecting the muscles that control eye alignment.

Management: Keeping blood sugar levels under control is crucial. Regular eye exams are also recommended to catch and manage any issues early.

Hyperthyroidism

How They Relate: Overactive thyroid can lead to muscle imbalances in the eye, potentially causing or worsening esophoria.

Management: Treating the underlying thyroid condition often alleviates eye-related symptoms. Antithyroid medications or surgery may be necessary.

Aging

How They Relate: With age, the muscles controlling eye movements may weaken, leading to issues like esophoria becoming more noticeable.

Management: Regular eye exams become increasingly important as you age. Prescription lenses with prisms or vision therapy may be recommended.

Stress and Fatigue

How They Relate: Both stress and fatigue put additional strain on the eye muscles, making it harder to maintain proper alignment and thus exacerbating esophoria symptoms.

Management: Stress management techniques like mindfulness and adequate rest can sometimes reduce symptoms.

Dry Eye Syndrome

How They Relate: Dry eyes can cause discomfort and make it difficult to maintain focus, which might exacerbate esophoria symptoms.

Management: Artificial tears or other treatments for dry eyes can help relieve symptoms and potentially make it easier to maintain proper eye alignment.

Autoimmune Diseases

How They Relate: Conditions like lupus or rheumatoid arthritis can affect various tissues in the body, including those around the eyes, which might contribute to esophoria.

Management: Treating the underlying autoimmune disease often requires a multidisciplinary approach that may include eye care.

High Blood Pressure

How They Relate: Chronic high blood pressure can cause damage to blood vessels in the eyes, potentially affecting eye muscle control and alignment.

Management: Blood pressure management through medication and lifestyle changes can be essential in such cases.

Migraines

How They Relate: Migraines can affect vision and put additional strain on the eyes, possibly making esophoria symptoms worse during episodes.

Management: Migraine medication and stress management techniques might help in reducing the frequency and severity of episodes, thereby alleviating the impact on esophoria.

Diagnosis of Esophoria

Proper diagnosis of esophoria is crucial for effective treatment and management. Eye care professionals use a variety of tests to evaluate eye alignment and pinpoint the underlying issue. Here's a look at some commonly used tests for diagnosing esophoria:

Cover-Uncover Test

What It Is: The cover-uncover test involves covering one eye with an occluder (usually a small paddle) while focusing on a distant object. This helps the doctor observe if the uncovered eye moves to refocus, indicating a misalignment.

How It Helps: If the uncovered eye moves inward or outward when the other eye is covered, it suggests that the eyes are not perfectly aligned. In the case of esophoria, the eye would drift inward when covered and then re-align when uncovered.

Alternate Cover Test (Cross Cover Test

What It Is: This test is similar to the cover-uncover test but involves rapidly switching the occluder from one eye to the other while the patient focuses on a target.

How It Helps: This test is particularly useful for detecting phorias, like esophoria, where the eyes maintain alignment under normal conditions but drift when the alignment is disrupted. If the eyes make a horizontal or vertical movement to refocus every time the cover is switched, it indicates a phoria.

Prism Cover Test

What It Is: In this test, prisms of different strengths are placed in front of one eye while the patient focuses on a distant object. The eye care professional observes how much the eye moves to maintain focus.

How It Helps: The prism cover test quantifies the degree of misalignment in prism diopters, which can be very helpful in determining the severity of the condition and planning the treatment accordingly.

Sensory Motor Evaluation

What It Is: A sensory motor evaluation (SME) or sensory motor examination consists of multiple measurements of the ocular alignment positions and may include tests of fusion and binocular (3D) vision. This test is covered by most medical insurance plans when there is sufficient medical need under the CPT code 92060. This test goes beyond the basic sensorimotor test that is performed in a standard eye exam.How It Helps: This test is extremely important and one of the most common tests among pediatric optometrists and ophthalmologists. The test provides a range of measurements that assist in diagnosing and treating binocular vision problems.

Esophoria vs. Esotropia: Understanding the Difference

Common Questions

Near esophoria, specifically affecting vision at close distances, is commonly treated with corrective lenses, prism glasses, or vision therapy. An optometrist may recommend exercises to strengthen the eye muscles and improve coordination. In some cases, bifocal or progressive lenses are prescribed to reduce the strain during near work. The treatment plan is tailored to the individual's specific needs and the degree of esophoria.
Esophoria can have a genetic component, as many eye alignment issues can run in families. However, it's also influenced by environmental factors and individual eye conditions. A thorough assessment by an optometrist can help determine the underlying cause and whether genetics plays a significant role in a particular case of esophoria.  
Certain neurological disorders, such as cerebral palsy, multiple sclerosis, stroke, or brain injuries, can cause esotropia, a condition where one or both eyes turn inward. These disorders can affect the nerves or muscles controlling eye movement, leading to misalignment. A thorough evaluation by an eye doctor is necessary to diagnose the cause of esotropia in such cases.  
To manage decompensating esophoria, where the inward turning of the eyes becomes more pronounced, eye exercises can be effective. These exercises, often guided by an optometrist, may include convergence exercises, pencil push-ups, and computer-based vision therapies. The goal is to strengthen the eye muscles and improve control over eye movements. Regular practice and follow-up with an eye care professional are key to success.
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