As children progress in school, they face increasing demands on their visual abilities. The size of print in schoolbooks becomes smaller and the amount of time spent reading and studying increases significantly. Increased class work and homework place significant demands on the child's eyes.
When certain visual skills have not developed, or are poorly developed, learning is difficult and stressful, and children will typically:
Avoid reading and other near visual work as much as possible.
Attempt to do the work anyway, but with a lowered level of comprehension or efficiency.
Experience discomfort, fatigue and a short attention span.
Vision is more than just the ability to see clearly. It is also the ability to understand and respond to what is seen. Basic visual skills include the ability to focus the eyes, use both eyes together as a team, and move them effectively. Other visual perceptual skills include:
Recognition (the ability to tell the difference between letters like "b" and "d"),
Comprehension (to "picture" in our mind what is happening in a story we are reading), and
Retention (to be able to remember and recall details of what we read).
Every child needs to have the following vision skills for effective reading and learning:
Visual acuity — the ability to see clearly in the distance for viewing the board, at an intermediate distance for the computer, and up close for reading a book.
Eye Focusing — the ability to quickly and accurately maintain clear vision as the distance from objects change, such as when looking from the board to a paper on the desk and back.
Eye tracking — the ability to keep the eyes on target when looking from one object to another, moving the eyes along a printed page, or following a moving object like a thrown ball.
Eye teaming — the ability to coordinate and use both eyes together when moving the eyes along a printed page, and to be able to judge distances and see depth for class work and sports.
Eye-hand coordination — the ability to use visual information to monitor and direct the hands when drawing a picture or trying to hit a ball.
Visual perception — the ability to organize images on a printed page into letters, words and ideas and to understand and remember what is read.
If any of these visual skills are lacking or not functioning properly, a child will have to work harder. This can lead to headaches, fatigue and other eyestrain problems. Parents and teachers need to be alert for symptoms that may indicate a child has a vision problem.
Signs that may indicate a child has vision problem include:
Frequent eye rubbing or blinking
Short attention span
Avoiding reading and other close activities
Covering one eye
Tilting the head to one side
Holding reading materials close to the face
An eye turning in or out
Losing place when reading
Difficulty remembering what he or she read
Accommodation is the ability to adjust the focus of the eyes as the distance between the individual and the object changes. Children frequently use this vision skill in the classroom as they shift their attention (and focus) between their book, or desk and the board for sustained periods of time. Being able to maintain focus up close for long periods of time is imperative for reading, writing and also taking tests.
Binocular fusion refers to the brain's ability to gather information received from each eye separately and form a single, unified image. When a child's eyes are not properly aligned it causes blurry vision, double vision, or eye strain, which leads to poor comprehension or avoiding reading altogether.
Convergence is the ability to turn the two eyes toward each other to look at a close object. This is an essential task when reading, completing homework, and using the computer or smart phone.
Treating reading-related vision problems
The optometrist examines these vision skills and determines how well the child is using them together. When a vision problem is diagnosed, he or she can prescribe glasses, vision therapy or both.
Vision therapy has proved very useful in treating reading-related vision problems. It involves an individualized program of training procedures designed to help a child acquire or sharpen vision skills that are necessary for reading.