Why Our Eyes Need to Work Together
We are born with eyes looking straight ahead and although each eye works separately, they are designed to work as a team. We have six muscles attached to each eye. The brain must coordinate these muscles perfectly so that we can see comfortably and efficiently. When the visual system is working correctly, the brain is able to ‘fuse’ the image from the right eye and the image from the left eye and sustain clear, comfortable single vision.
When Eye Teaming Fails
However, if this coordination is difficult, eyesight may be clear at times but blurry or double at other times. Our unconscious efforts to prevent blurred or double vision can cause fatigue, eyestrain, headaches as well as loss of attention and comprehension during reading, near work or computer work. Children with this problem in particular can be easily distracted and can find it difficult to concentrate and remain on task. Parents often comment that completing their homework takes a very long time!
About ten percent of school-aged children have eye teaming problems. So why don’t children complain? Because they can’t compare their vision, they think its normal for them to see this way. They don’t realise that they are working their eyes much harder than their friends to see a single, clear image.
Types of Eye Teaming Difficulties
Eye teaming problems are usually diagnosed as either:
Sometimes, a child might cover one eye or lie their head on the table in an effort to stop seeing double. In extreme cases, poor eye muscle coordination can even cause eye turns (strabismus) and/or lazy eyes (amblyopia). Children with very poor eye teaming will not be able to appreciate 3-D movies the way it is meant to be and may complain of headaches and eyestrain when trying to watch one.
Why Eye Teaming Matters
Left untreated, eye teaming problems may show up as a learning difficulty (for example, falling behind in reading) or dyslexia. This is not the case. Eye teaming problems are visual efficiency problems, not language-based reading dyfunctions. The symptoms, however, are similar and only a comprehensive eye exam by an optometrist trained to diagnose and treat eye teaming problems can determine if vision is the basis of the child’s struggle to read.
Symptoms of Teaming Problems
- Closes or covers one eye
- Occasionally sees double
- Rubs eyes frequently
- Able to read for a short time only
- Poor reading comprehension
Treatment and Management Options
There are two main forms of treatment for Convergence Insufficiency:
ACTIVE TREATMENT: Vision Therapy
Vision therapy has been cited as the most effective treatment method for Convergence Insufficiency(1). Therapy sessions will be based around enhancing the ability of the eyes to turn in evenly and comfortably. This can be achieved in the clinic and reinforced with home exercises.
PASSIVE TREATMENT: Prism glasses
Prism glasses are a good way of treating the symptoms, however they are ineffective in curing the Covergence Insufficiency itself. They have been known to provide relief in the short-term, however cannot solve the root cause of the problem.
Our optometrists and vision therapists will discuss the best treatment modalities for your case.