Vision Therapy for Convergence and Focussing Problems – A Detailed Review
This latest review of convergence insufficiency is an comprehensive review on this common vision problem, its impact and management. What I like about this article is that one of the authors, Dr Cooper is an excellent clinician, as well as a researcher. This provides valuable clinical pearls and insights into the interpretation of the research surrounding this common but under-diagnosed vision problem.
While the review is directed at health professionals, a summary of the key findings is useful for teachers, patients or parent of a child who is showing signs of problems with attention, learning, reading or visual discomfort, where there is a potential for a convergence or focussing problem to exist.
History and Prevalence
It’s incredible to discover that convergence insufficiency was first described nearly 160 years ago, and the exact cause is still unknown. While many practitioners tend to describe the condition as an “eye” or “muscle” problem, it is increasingly becoming clear that it is more functional in origin ie it is the brain’s control over the eyes that is the issue.
It is estimated up to one in twelve people have convergence insufficiency, with up to 1 in 5 showing risk signs associated with the condition. Clinician’s observe that it seems to “run in families”. There is a 3x greater prevalence of ADHD in children with CI and vice versa.
As a clinician, I have often discussed with parents that children tend to show less obvious pain related symptoms and more behavioural signs (hence the “behavioural” in behavioural optometry). Children will tend to drift-off, lose attention, get frustrated or avoid tasks (like reading and writing), rather than put up with discomfort. Where-as older children, teens and adults will tend to present with the more classic and obvious discomfort symptoms. Studies have demonstrated this to be true also in tightly controlled research groups. However, patients of all ages will tend show a mix of both performance, behaviour and eye symptoms.
Reading, Writing or Computer Performance Related Symptoms
- reduced comprehension, or remembering what is read
- losing place
- losing concentration
- reading slowly
- difficulty completing homework
- difficulty completing assignments
- careless errors
- avoidance and/or dislike of close work
Eye Related Symptoms
- frontal headaches
- eye ache
- a pulling sensation
- heavy eyelids
- double vision
- blurred vision
- watery eyes
- dull eye pain or pain behind the eyes
Less Common Symptoms
- poor depth perception
- nausea, feeling sea-sick or giddy
- car and/or motion sickness
- difficulties with parking the car or judging depth in sport
Injury & Health History
Convergence insufficiency is associated with mild head trauma, whiplash, and Parkinson’s Disease.
If you are suffering the above mentioned symptoms, a comprehensive vision examination can be arranged.
Assessment for Convergence Insufficiency
Many of the symptoms above will only be expressed by patients, particularly children if a careful interview or “case history” is done. Many patients just present because they simply sense that something is not right, or some aspect of schooling performance is not up to a particular standard.
Likewise, not all eye exams are likely to adequately assess for convergence insufficiency (CI). Cooper and Jamal’s review indicate that detection of CI requires multiple tests, including also assessing focusing ability and may also require additional testing in order discover the problem. They also indicate that shortsighted-ness, longsighted-ness and other refractive “sight” errors are not associated with CI. This obviously indicates the practitioner needs to look at more than just sight to diagnose vision problems of this nature.
Learning, reading and attention
CI and focusing difficulties have been associated with learning and reading difficulties. While CI is not a cause of these conditions, many of the symptoms appear to be reading related. There is a large study underway to explore the effect of vision training for CI on attention and reading. This is not to be confused with children who have genuine reading disabilities like dyslexia, although symptomatic children can still benefit from reduction of visual symptoms and the interference they will cause.
The most successful treatment for convergence insufficiency is office based vision therapy or vision training. Treatment success decreases significantly for other forms of vision therapy, so it is important to understand the difference when discussing vision training with an optometrist, or another professional who may not understand the in and outs of vision therapy in detail.
Types of Vision Therapy
- Office Based Vision Therapy – weekly or fortnightly one-on-on sessions with a trained vision therapist tailors the vision therapy session specifically for each patient, and is coupled with home reinforcement or practice. The therapist is able to observe, provide immediate feedback and adjustment, and can control vital ingredients like motivation and compliance to the program. Not surprisingly, this is the most effective form of vision therapy as it’s like having a personal trainer for your visual system. Once vision therapy is complete the results have been proven to be long-lasting.
- Pencil Push-Ups – this is one of the most prescribed forms of vision training, and has been clearly demonstrated be in-effective when compared to office based vision therapy.
- Home Based Computer Vision Therapy – an attractive option for both patient and practitioner as it is relatively low cost to both parties, has the image of being modern, and is convenient. The reality is that computerised vision therapy done at home does not benefit from much optometrist or therapist input on observing whether the patient’s response is correct and relies on an untrained parent to judge and provide feedback. Studies have shown that it is no more effective than pencil push-ups.
- Prism Glasses – while tempting because they are simple, they haven’t been shown to be effective.
- Reading lenses – not a stand-alone treatment for CI, but if patients to also have focusing problems, these can be useful for reducing symptoms. More research is required to understand these better and how they are used as a stand-alone treatment when a focusing problem is found in isolation or for people suffering computer vision syndrome.
- Tinted or Coloured Lenses – used as a last resort if a person still has symptoms after vision training or reading lenses.
To find out more, or suspect convergence insufficiency, please contact us. We are a Gold Coast based Optometry and Vision Therapy Clinic.