When Glasses Aren’t Enough: An Overview of Vision Therapy
By: Janelle J Brown, OD
Optometrists are well established in treating eye health and refractive correction services. However, there is another piece to the puzzle: ensuring our patients have clear, comfortable binocular vision. In spite of an accurate glasses or contact lens prescription, some patients suffer from double vision, eyestrain, fatigue when reading, poor reading comprehension, or words jumping around the page. In addition to the annoyance of headaches and the confusion of double vision, these conditions may prevent the person from seeing 3D or negatively impact school/work performance. Many of these symptoms are related to an inefficient binocular system, meaning the two eyes don’t team well together. Vision therapy teaches these skills and improves overall visual performance.
Patients are considered as vision therapy candidates based on the concerns and symptoms they describe at their appointment and on the doctor’s evaluation of eye position, eye teaming, and focusing. The optometrist will likely bring the patient back for more in-depth binocular vision testing to determine if the patient would benefit from vision therapy. In addition, this evaluation gives the patient and doctor an opportunity to discuss expectations, treatment time frame, and concurrent home therapy.
The optometrist will develop a treatment plan based on the type and severity of the particular condition(s) the patient has. Therapy sessions can be performed by the prescribing optometrist or a vision therapy assistant. The first few weeks of therapy are quite straining as the patient is learning new techniques. I tell my patients to expect a headache if they are working hard enough during their sessions. Depending on the condition, training can take 8 weekly sessions up to many months. Generally, office vision therapy is accompanied with simple home tasks to reinforce skills throughout the week until the next session.
A common misperception is that vision therapy strengthens the eye muscles. In truth, the eye muscles are strong enough for the tasks at hand, they just don’t know “how” to position, focus, or adjust effectively. Thus with repetitive vision training tasks in office, we develop these skills to become more automatic. Techniques include the use of charts, lenses, prisms, devices that help create 3D vision, and red/green filters.
The 4 main categories treated by vision therapy include: amblyopia, eye movement, focusing, and vergence. Often, patients have problems with several of the categories, so our treatment plan progresses from basic to more difficult tasks. We treat decreased best corrected vision (amblyopia) first by patching the better seeing eye so that the poorer seeing eye can develop better vision. Next, eye movement problems such as pursuits (using your eyes to track a moving object) and saccades (jumping your eye position from one object to another) are addressed. Both of these skills are critical to reading speed, accuracy, and comprehension. The third category, focusing, includes treating patients who have difficulty stimulating focus, relaxing focus, or difficulty adjusting from focusing to relaxing. The final category of vergence relates to moving both eyes equally inward to the nose (convergence) or outward towards distance (divergence). For example, those with “eye turns” or strabismus are manifesting a loss of vergence control. It is much easier to train an intermittent eye turn than a constant eye turn. Once deficiencies in these areas have been addressed, we integrate skills from multiple categories so that they become second nature and with practice, require minimal effort.
Once treatment is complete, occasional home therapy is recommended. Once the skills have been learned, they should last a lifetime with minimal maintenance or rare refresher training sessions. Traditionally, vision therapy is used most often to treat school-aged children, but can be used for patients who experience these problems at any age. Additionally, some sub-specialties of vision therapy include neuro-optometric rehabilitation for those recovering from strokes or traumatic brain injury and sports vision enhancement for athletes wanting to improve their reaction time and eye movement skills.
Personally, I enjoy the reward of working with vision therapy patients. It is amazing to see the dramatic improvement in patients’ grades and improved quality of life in a matter of weeks or months. My goal is to create a positive and fun learning environment and teach skills that not only relieve symptoms but improve the visual comfort of everyday tasks. In the classroom or workforce, the last thing you should worry about is your eyes keeping up.