By Dr. Charles J. Bock

Convergence Insufficiency

Convergence describes the movement the eyes make when changing their focus from a distant object to a near one. To an observer, the eyes appear to cross, but this "crossing" (bringing the eyes closer together) is needed to bring both eyes into focus on the nearer object.

Convergence insufficiency is a term used to describe a very specific problem. People with convergence insufficiency have difficulty keeping the eyes converged for prolonged periods of time. They complain of headaches with reading or other near work that often begin 15 to 30 minutes after they begin to read. Some people notice double vision or blurred vision, as well. On examination, people with convergence insufficiency have very specific findings. The most important is that their convergence amplitudes (amount of convergence they are able to achieve) are less than normal.

While many people complain of headaches, only those with the type of headache associated with convergence insufficiency and an examination that shows decreased convergence amplitudes are diagnosed with convergence insufficiency. Although this is a disorder which is frequently under-diagnosed, it is important not to over-diagnose it in cases which do not meet the strict criteria, because only people with true convergence insufficiency benefit from its treatment.

Convergence insufficiency is most often seen in normal, healthy people of any age. It is also seen more frequently in people who have had head trauma and in people with Parkinson's disease. Convergence insufficiency associated with Parkinson's disease can be particularly difficult to treat.

Types of Treatment

Most people are best treated for convergence insufficiency without surgery. Non-surgical treatment may include glasses in some patients, but for most patients, eye exercises are needed. These exercises have been proven to be beneficial, and are not the same as vision therapy (which is sometimes recommended to treat learning and reading disorders and has not been proven effective for those problems).

Most patients begin with a series of exercises (described in separate handouts) which are geared toward using the convergence the patient already has. These exercises help make the patient aware of the act of converging and help prepare the patient for more difficult exercises aimed at increasing convergence. Most patients will be asked to perform these exercises for 15 minutes per day (which can be divided into two or three shorter sessions) for four to six weeks.

Next, prism exercises (described in a separate handout) are prescribed. These are used to help increase the patient's amount of convergence, to help prevent fatigue. Full treatment with prisms usually takes twelve weeks, although many patients report a marked improvement in their symptoms very early in their treatment.

In rare cases, surgery may be necessary.

If you have additional questions

Once you return home, you may have additional questions or you may need clarification regarding the exercises that have been recommended. Please feel free to call our office 503-656-4221 at any time with any questions you have. Our goal is that you understand completely your condition and treatment.