The following is a list of visual skills necessary for learning:
Tracking – the ability to follow objects with your eyes. It involves smooth coordinated movements, as well as movements from one target to another. Tracking is vitally important when reading. You must be able to move your eyes accurately when reading in order to get the full meaning from the words printed on a page. Problems with tracking are often noticed when children or adults skip words or lose their place while reading. They may also flip the beginning and endings of words or reread the same sentence over again.
Fixation – the ability to find and look at a series of stationary objects, such as words on a page. We determine what to fixate upon with a combination of peripheral awareness (knowing what is available within our entire field of view) and a mental determination of what is of value to view more closely. When fixation ability is poor, words may appear to be moving or swimming around on the page.
Focus Change – the ability to look from one distance to another, such as looking at the chalkboard and then back to a workbook on our desk. When the focusing system does not focus properly, words will be blurry or things may seem to go in and out of focus. Fatigue can set in quickly and can lead to headaches or double vision.
Binocularity – the ability to look together with both eyes at the same time. A child acquires eye teaming skills during the preschool years. Lack in this area will result in poor judgments of spatial orientation and depth perception. More importantly, binocular vision problems can affect the presence and accuracy of single, clear vision for objects far and near. Problems can be noticed in sports performance and accuracy with driving a car.
Peripheral Vision – the ability to be aware of objects and things around your body without direct eye contact. It is also very important to be able to accurately integrate central and peripheral vision at the same time. This helps us filter out unimportant visual stimuli and concentrate on the more important ones. Lack of central and peripheral vision integration is particularly prevalent in children with ADHD as well as children who have autism spectrum disorders.
Visual Discrimination – the ability to detect similarities and differences between objects. The process of visually matching objects happens very early in childhood. Knowing and recognizing small differences comes next in development and is critical in learning to function in a visual world. Visual discriminatory knowledge is a precursor necessary for learning to read and write.
Basic visual skills such as those described above are often observed with infants and toddlers. Higher level visual capabilities, which typically begin after 2 years of age, include visual imagery, visualization, visual recall, and visual thinking. Cumulatively, they are used for success in academics, problem-solving, receptive and expressive communication, and graphic capacities that include writing and drawing.
Children who have gaps in their visual development often have difficulty with spelling, reading comprehension, memorizing lists and tables, following multiple instructions, and solving problems with visual cues. Adults with visual development gaps often compensate by learning through alternative means, but they may still have difficulty following driving directions, judging distances, and studying.
Developmental vision therapy is designed to help people develop higher order vision capacities, to fill in gaps in vision development where they have occurred, and to ensure utilization, along with our other capacities, for learning and understanding. This is accomplished by creating developmentally appropriate conditions for each individual, in which the only way to achieve a given objective is to explore one or more of these visual capacities.