Excess convergence is a visual impairment that affects the child’s ability to maintain the coordination of both eyes when focusing on an object close to the nose. Actually, the anomaly is caused by a bad coordination of the internal rectus muscle of the eyes that tenses too much and causes the eyes to align excessively towards the nose. It usually happens at very early ages , in children whose visual system is still developing and have difficulty in eye coordination.
CAUSES
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Diseases affecting the alignment of the eyes
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Refractive defects such as children who have uncorrected farsightedness.
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Genetic factors
SYMPTOMS
Symptoms may include:
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headache
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itchy eyes
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blurred vision: especially when there is concentration of near vision for a certain time, for example, reading a book for 30 minutes.
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tearing
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double vision
The excess of convergence is measured in diopters, normally when they are low anomaly values, usually do not cause any symptoms because the visual system itself is responsible for compensating for this anomaly. When there are symptoms, it is really because the visual system itself is making an effort to try to align the eyes and be able to see well. These symptoms, can be treated with vision therapy. If the anomaly presents a very high value and the eye is very deviated, it is because the oculomotor system is making an effort but is not able to correct the anomaly. On this case, the anomaly can be improved with vision therapy or a surgery to try to solve the problem.
TREATMENT
Convergence excess is usually treated with visual training exercises, which consists of working on the coordination of both eyes equally. This should be done with an optometrist. In each session the exercises are performed and in addition, exercises should also be done at home. In early ages and children around 7 years old, this therapy has very good results. Doing this sequence of exercises means that the symptoms will be greatly reduced.
Another option that is also used to reduce symptoms and accelerate treatment are optical aids with glasses with a positive prescription to relax the eye muscles or prisms that help reduce double vision or contact lenses.