As we know, we have two eyes. This means in order to have clear vision both eyes need to be equally and accurately tuned, while working together, to create images.
Thus, we have what is called the binocular vision system—the system which monitors and controls both eyes so that they work harmoniously to create what we perceive as vision.
The binocular vision system is very complex and has many different parts to it. The major two components of the binocular vision system are oculomotor function and accommodation.
Like the rest of the body, the eyes have muscles which control their movements and allow us to look in different directions.
The control center for eye movements is called the oculomotor system and is very fine-tuned to allow the eyes to stabilize images when walking around, to look in different directions, and even just to keep the two eyes working together instead of each eye operating separately!
Not only that, but the eye also has its own focusing system called the accommodative system.
The accommodative system is what we use to look at an object far away and up close. As we get older, this system weakens and is no longer able to function as well, however up until the age of 45 or so this system is an essential part of the visual process!
With all this said, the eyes have many moving parts to allow for clear vision. Even a small problem with just one of the muscles, or with the accommodative system, the imaging processing system, etc. can cause serious ocular discomfort and poor vision.
Vision therapy is essentially physical therapy specific to the eye muscles and focusing system.
Specialized therapists (vision therapists, optometrists, and some occupational therapists) work with an individual to create a personalized plan to help strengthen and fine-tune the ocular system to improve symptoms associated with oculomotor and accommodative problems.
Binocular vision problems (conditions in which the two eyes do not work effectively together) are the main conditions vision therapy treats.
Binocular vision problems can be further broken down into two major categories—accommodative disorders and oculomotor disorders.
Accommodative disorders reference the focusing system and the eyes’ abilities to accommodate equally and accurately.
If the accommodative system of one or both of the eyes is too weak, it is called accommodative insufficiency. Individuals with accommodative insufficiency often complain of eye strain, fatigue, the feeling of though his/her arms are not long enough, and the inability to keep near objects clear for very long.
These individuals will struggle with reading, writing, computer work, etc., especially towards the end of the day when they eyes become tired.
Alternatively, if the accommodative system of one or both of the eyes is too strong it can spasm, locking the focusing system of the eyes on an up-close target, making objects far away blurry. Individuals in this situation (too much accommodation) suffer from a condition called accommodative excess or accommodative spasm.
As stated above, this condition results in vision far away being blurry for extended periods of time after near tasks (reading, writing, computer work, etc.), which can also result in eyestrain, headaches, and fatigue.
On the other hand, oculomotor dysfunction involves the eye muscles not coordinating effectively, resulting in eye strain, fatigue, and often times double vision.
There are many different types of oculomotor problems that can be improved upon via vision therapy. These problems include eye turns (tropias), convergence problems (both eyes moving inwards, such as when looking at a near object), divergence problems (both eyes moving outwards, such as when looking at a distant object), and image tracking problems.
Before vision therapy begins, your optometrist will want to run several different tests to determine the abilities of the visual system—this visit is often referred to as a binocular vision evaluation or sensorimotor examination.
Your doctor will be able to determine what is going on with your eyes—maybe you have an accommodative disorder, or perhaps you have one muscle that’s a little weaker than the rest, whatever the cause the first step is to determine the limits of your system and find the underlying problem.
Since the binocular system is one unit, both the oculomotor aspect and accommodative aspect are connected. In some cases, you may be overworking one of the systems to compensate for weakness in the other. Or maybe both the accommodative system and the oculomotor system are weaker than normal!
For this reason, it is important to test both aspects of the binocular system—accommodative and oculomotor—to determine what is going on and create a tailored plan to your individual case. In some cases, vision therapy may not be the primary treatment.
However, vision therapy can be a saving grace to many individuals and create eye comfort that may previously never been thought possible.
We’ve talked about why someone might need vision therapy, and how to go about testing the binocular system, but what is actually done at vision therapy?
A therapist will take your tailored plan and help you perform exercises to strengthen your binocular system.
In many cases, the system just needs to be adjusted and recalibrated to work more efficiently. The best way to do that is through exercises that force the muscles to work as they should.
Examples of exercises include focusing on objects at near and far, forcing the eyes to focus through various lens powers, usage of special 3-D devices, computer programs, and more!
Vision therapy is a process. Just like one visit to the gym will not grow massive muscles overnight, vision therapy will not fix the eyes in just one session.
Vision therapy will include several weeks of in-office therapy sessions and even homework activities to be completed daily.
The ultimate goal of vision therapy is to strengthen the area that is lacking to reduce symptoms and create a better functioning visual system.
If you, or someone you know, is interested more in vision therapy and what it could do for you, be sure to reach out to your local optometrist today!