Exophoria: Symptoms, Causes, Treatment

What are the symptoms of exophoria?

Exophoria is a type of eye condition where the eyes tend to drift outward, away from focusing on an object at close range. It’s a form of strabismus, or eye misalignment, that typically occurs intermittently, meaning the eyes only drift outward occasionally. Symptoms of exophoria can vary depending on the individual and the severity of the condition, but they may include:

Eye strain: Especially after prolonged periods of close work, such as reading or using a computer.
Fatigue: Particularly during or after activities that require visual concentration.
Headaches: Often located around the temples or forehead.
Difficulty concentrating: Especially on close-up tasks.
Double vision: Though this is less common and tends to occur more frequently when exophoria is more severe.
Dizziness or vertigo: Some individuals may experience a sense of imbalance or dizziness, especially when the eyes are not properly aligned.
Difficulty with depth perception: A tendency to misjudge distances.
Eye discomfort: Including dryness, itchiness, or a feeling of grittiness.

Exophoria can often be managed with vision therapy, prism glasses, or other treatments prescribed by an eye care professional. It’s important to have regular eye exams to monitor the condition and ensure appropriate management.

What are the causes of exophoria?

Exophoria, like other forms of strabismus, can have various causes, including:

Muscle imbalance: Weakness or imbalance in the muscles that control eye movement can cause the eyes to drift outward.
Refractive errors: Uncorrected or undercorrected refractive errors, such as farsightedness (hyperopia), can contribute to exophoria, especially when focusing on close objects.
Fatigue or eyestrain: Prolonged periods of close work, such as reading or using a computer, can lead to temporary exophoria due to muscle fatigue.
Neurological conditions: In some cases, neurological conditions or abnormalities in the brain can affect the control of eye movements and lead to exophoria.
Genetics: There may be a genetic component to exophoria, as it can run in families.
Systemic health conditions: Certain systemic health conditions, such as thyroid disorders or diabetes, can affect eye muscle function and contribute to exophoria.
Eye injuries or trauma: Injuries to the eye or surrounding structures can sometimes lead to muscle weakness or imbalance that results in exophoria.
Eye surgery: Previous eye surgery, particularly if it involves the eye muscles, can sometimes lead to exophoria.

The exact cause of exophoria can vary from person to person, and in many cases, the cause may not be clearly identifiable. It’s important to consult an eye care professional for a comprehensive eye exam if you suspect you have exophoria or any other eye condition.

How is the diagnosis of exophoria made?

The diagnosis of exophoria is typically made through a comprehensive eye examination by an eye care professional. Here are some common steps in diagnosing exophoria:

Visual acuity test: This test measures how well you can see at various distances. It helps determine if refractive errors, such as nearsightedness or farsightedness, are contributing to your exophoria.
Cover test: During this test, one eye is covered while you focus on a distant object, then the cover is switched to the other eye. This helps the eye care professional detect any misalignment or drifting of the eyes.
Ocular motility test: This test assesses the movement of your eyes in different directions to evaluate eye muscle function and coordination.
Near point of convergence test: This test measures how close an object can be before your eyes start to drift outward. It helps evaluate convergence ability, which is important for focusing on near objects.
Refraction test: This test determines your eyeglass prescription to correct any refractive errors that may be contributing to your exophoria.
Binocular vision assessment: This includes tests to evaluate how well your eyes work together as a team, such as the use of stereoscopic tests to assess depth perception.
Evaluation of symptoms: Your eye care professional will also ask about any symptoms you may be experiencing, such as eye strain, double vision, or headaches, which can help in the diagnosis of exophoria.

Based on the results of these tests, your eye care professional can determine if you have exophoria and recommend appropriate treatment, which may include vision therapy, prism glasses, or other interventions.

How is exophoria different from esotropia?

Exophoria and esotropia are both types of strabismus, or eye misalignment, but they involve different directions of eye deviation.

Exophoria: Exophoria is a tendency for the eyes to drift outward, away from focusing on an object at close range. It typically occurs intermittently, meaning the eyes only drift outward occasionally, especially during periods of fatigue or eyestrain. Exophoria is often associated with near vision tasks and can sometimes be controlled or corrected by the brain without noticeable symptoms.
Esotropia: Esotropia, on the other hand, is a type of strabismus where one or both eyes turn inward, towards the nose, when focusing on an object. Unlike exophoria, esotropia is usually constant and can occur at both near and far distances. Esotropia often results in double vision (diplopia) and may be associated with other vision problems.

In summary, the main difference between exophoria and esotropia is the direction of eye deviation: exophoria involves outward drifting of the eyes, while esotropia involves inward turning of the eyes. The two conditions also differ in terms of their frequency, associated symptoms, and impact on vision.

What is the treatment for exophoria?

The treatment for exophoria depends on the severity of the condition and the presence of any associated symptoms. Here are some common approaches to managing exophoria:

Observation: In some cases, especially if exophoria is mild and not causing significant symptoms, no treatment may be necessary. Regular eye exams to monitor the condition may be recommended.
Vision therapy: Vision therapy, also known as orthoptics or vision training, is a structured program of visual activities designed to improve eye coordination and focusing abilities. It can be beneficial for individuals with exophoria, especially if it is causing symptoms such as eye strain or fatigue.
Prism glasses: Prism glasses can help correct the alignment of the eyes and reduce symptoms of double vision or eye strain associated with exophoria. The prisms in the glasses help align the images seen by each eye.
Corrective lenses: If refractive errors, such as nearsightedness or farsightedness, are contributing to exophoria, prescription lenses may be prescribed to correct these errors and reduce eye strain.
Surgery: In some cases, especially if exophoria is severe or causing significant symptoms, surgery may be considered to realign the muscles that control eye movement. However, surgery is typically reserved for cases that do not respond to other treatments.
Lifestyle modifications: Making lifestyle changes, such as taking breaks during prolonged periods of close work and practicing good eye hygiene, can help reduce symptoms of exophoria.

It’s important to consult an eye care professional for a comprehensive evaluation and personalized treatment plan if you have exophoria. Treatment options will depend on your specific needs and the underlying causes of your condition.