Convergence Excess

Dr. Russel Lazarus, July 11, 2021

According to the American Optometric Association, convergence excess affects over 7% of children, which can impact a child’s ability to learn.

The eyes have six muscles, known as extraocular muscles. These muscles are responsible for moving the eyes in tandem in all directions. They enable effortless synchronization of the eyes at all distances and ranges of vision in perfect synchrony, all day long.

We need our eyes to converge, look inwards towards the nose, in order to perform near activities like reading. The eyes’ inability to converge can cause double vision and eye strain, this is a condition known as Convergence Insufficiency.

What is convergence excess?

Convergence excess is an eye condition where there is an imbalance in the eye muscles causing them to not work perfectly together; rather, one eye aims too close or in front of an object.

For someone with convergence excess, the eye muscle coordination system must work harder to maintain alignment. Sometimes the extraocular muscles are overworked to the point where they can no longer sustain single, binocular vision, resulting in episodes of diplopia (double vision), fatigue or headaches and migraines.

In situations like this, people with convergence excess will either see double, or the brain will learn to suppress the vision from one eye.

Untreated convergence excess can lead to lazy eye or even an eye turn, known as esotropia.

Convergence Excess and Eye Turns

Esotropia, a form of convergence excess, is a form of eye turn, which causes one eye to turn too far inward compared to the other eye.

For children with convergence excess, copying from the blackboard can often be very difficult. Also, when children move a book closer or farther away to see better, they are actually attempting to alleviate their convergence excess difficulties.

These children may use only their stronger eye when they come close enough to the page, reducing the confusion and strain of trying to use both eyes simultaneously.

This convergence excess is commonly associated with accommodative dysfunction. In an attempt to compensate for reduced focusing strength, the eyes are directed closer in than desired, causing fatigue and tiredness.

What are symptoms of convergence excess?

Those with convergence excess tend to experience their symptoms while doing close work on a computer or reading.

They may experience any combination of the following symptoms, which often worsen towards the end of the day:

  • Headaches
  • Blurred vision
  • Eyestrain
  • Difficulty concentrating
  • Difficulty reading
  • Difficulty with reading comprehension
  • Double vision
  • Feeling tired while reading
  • Sleepiness
  • Slow reading
  • Words moving on the page

If you or a loved one experience any of the above symptoms, schedule an appointment with an eye doctor near you.

SEE RELATED: Convergence Insufficiency and Reading

Find a Vision Therapy Eye Doctor Near You

Convergence excess treatment

Vision therapy is a personalized treatment program that utilizes exercises that retrain the brain and eyes to work together.

For convergence excess, the goal of vision therapy is to allow the eyes to easily work together.

To do this, vision therapy utilizes  a combination of prescription glasses and prism to help train the eye muscles. When a prism is placed in front of one eye, it must move in order to maintain focus on a target. When prisms are used in eyeglass lenses, they allow the eyes to be in their most natural posture, resulting in constant, single vision.

A vision therapy program customized to treat convergence excess and will improve the accuracy of your eye movements and relax the visual system so vision is effortless and automatic.

LEARN MORE:   Vision Therapy for Children

If you or your child suffers with tiredness or eyestrain, schedule an appointment with an eye doctor near you to provide a diagnosis and treatment options.