Eye Teaming - The eyes do not work well together
When we look up close to read, both of our eyes have to turn inwards to point where we want to look. For some, this is difficult, it takes a lot of effort, or after a little while, one eye will start to drift out. This can make it look like words are moving on the page, or make it difficult to concentrate. It can make it hard to keep place and attention while reading or doing other school work, computer work, or other activities up close. For some, they avoid the activity without really knowing why. Headaches are also a common symptom because of the extra effort.
Of all the conditions treated by vision therapy, this is one of the easier ones to treat, though still takes practice and dedication. Therapy works to strengthen the inward movement of the eyes, and improve the ability of them to move together and work together.
Lenses, prisms, filters and 3D dimensional pictures are used to gradually increase the demand on the eyes and strengthen them.
Convergence Insufficiency is also a condition that can affect distance vision. It can cause intermittent blurry vision, or even double vision. Sometimes people think they must need glasses, but instead it is that their eyes are not working as well together as they should. This can affect distance depth perception, which is especially important for driving and sports performance. Depth perception and how well the eyes work together can be improved with vision therapy,
Moving the eyes outwards in a coordinated manner is called divergence. We move our eyes outwards and inwards (convergence) depending on where we are looking. There is a normal range or strength that can be measured for these movements. For divergence insufficiency, oftentimes, the eyes naturally want to rest inwards and there is not enough strength to compensate for this to move the eyes outwards to keep them pointing where they should. This can cause blurred vision, double vision, headaches, or avoidance of doing the visual task.
Divergence insufficiency is also a condition that can happen with distance vision to cause blurry or double vision.
Vision therapy can treat divergence insufficiency. Lenses, prisms, filters and 3D dimensional pictures are used to gradually increase the demand on the eyes and strengthen them.
When we look at something up close, our eyes need to focus more (accommodate). This should be easy at automatic, especially for young people. But, for some, maintaining focus takes much more effort than it should. This could lead to headaches or avoidance of reading or near work.
In some cases, reading glasses can help. However, if the range of focus is narrow, the eyes have trouble both increasing focus and relaxing focus, then reading glasses will not help. Additionally, if another condition is present, like convergence insufficiency, the reading glasses can make this condition worse. Vision therapy can improve the amount the eyes can focus, which can be measured and compared to a normal value, as well as treat other coexisting visual conditions.
Accommodative Infacility happens when the eyes cannot change focus as quickly as they should. Whenever we change where we are looking, especially at different distances, our eyes have to change focus. We can measure the speed this happens. If slow, tasks like copying from the board can be more difficult, as well as visual processing speed for a lot of different activities and sports.
Accommodative facility can be measure one eye at a time, and both eyes together. Some do fine when just using one eye at a time, but really struggle when they have to use their eyes together to change focus. In this case, sometimes the brain suppresses vision from one eye, so only one eye is being used. This affects depth perception and efficiency and ease of vision.
Accommodative infacility is almost always associated with another visual condition as well and can be treated with vision therapy.
Narrow Range of Focus
Tracking Difficulties - Saccades and Pursuits