What is an Eye Teaming Problem?
Eye teaming (also known as binocular vision) is a visual skill that allows both eyes to work together in a precise and coordinated way. Good eye teaming allows a person to maintain single, comfortable vision for a sustained period of time. It is also the basis for superior depth perception.
If there is a problem with eye teaming, objects can appear double or seem to move, which creates a confusing and uncomfortable view of the world. Symptoms of an eye teaming problem include double vision, headaches, blurred vision, and eyestrain, especially while completing near work such as reading and computer activities. Eye teaming problems occur in approximately 5-10% of children and adults.
The two most common teaming problems are convergence insufficiency and convergence excess. Convergence insufficiency is when the eyes have a tendency to turn out during reading and other near work. The visual system must exert extra effort to keep the eyes from drifting out. This extra effort can result in headaches, eye strain, and double vision. Convergence excess is when the eyes have a strong tendency to turn in during reading other near work. Symptoms are the same as convergence insufficiency. Most routine eye exams and screenings do not detect these problems.
More dramatic forms of eye teaming problems are called strabismus, which is when an eye can actually be seen drifting or wandering at times.
This is what an eye teaming problem may look like while reading:
What is a Focusing Problem?
We must refocus our eyes when we look from one distance to another. Most people are unaware of this change in focus because our visual system typically operates very efficiently and objects always appear in focus. In reality, a focusing adjustment is made every time we look from one place to another with the help of the ciliary muscle. The medical term for this is accommodation.
When a child looks from the board to her desk, she must contract or tighten this muscle. This causes the lens of the eye to change shape and allow the child to see print clearly. When the child looks back to the board, the focusing muscle must then relax to see clearly in the distance.
Problems with the focusing system occur when an individual is unable to quickly or accurately contract or relax the focusing muscle, or if the muscle contraction cannot be maintained for an adequate period of time while completing reading or other near work. Focusing problems can cause headaches, blurry vision when switching focus locations, eye strain, and uncomfortable vision while completing near work.
A focusing problem looks like this:
What is a Tracking Problem?
For us to use our vision efficiently, our eyes must move accurately and smoothly from one location to another. Our eyes jump from one word to another while reading and must do so accurately to allow for cohesive reading. Tracking is also important to follow moving objects in sports. Good hand-eye coordination starts with accurate eye movements.
Tracking skills are considered a fine motor skill. Like other fine motor skills, tracking will continue to develop and improve as a child gets older. Tracking problems will result in slow, inaccurate reading which will affect reading fluency and comprehension.
Tracking problems exhibit themselves with frequent loss of place during reading, skipping lines, omitting and substituting words, head movement, finger pointing, slow reading speed, poor copying, and poor hand-eye coordination.
This is what reading looks like with a tracking problem:
“The initial problem I had experienced was the inability to focus on text that I was reading due to the text doubling upwards, inability to concentrate, headaches, and my eye had kept skipping lines. This problem had a great effect upon my educational capabilities such as my ability to read text effectively. I was the slowest reader in my entire class everyone would have finished reading a section of a passage when I would still be half way done. This was due to me skipping lines unintentionally and having to go back and re-read what I have missed. Since I started the therapy my vision had gradually increased at a high rate that astonished myself. I no longer have headaches, double vision, and inability to maintain concentration. In the beginning of the therapy I had experienced a lot of pain such as headaches from the assigned computer homework. This only lasted for around the first two weeks. Overall I have had one of the best medical experiences I have ever had, and I have had many. Initially I had thought that therapy would be drag and something I was going to dread, but just with the first session my entire state of mind was changed. This was due to the marvelous care I was presented with during the start of my therapy. I was always greeted with a warm smile and was sent off with an even warmer smile. In addition, every time I completed a session I left with joy knowing that my eyes were getting better.”