- Eye Movement Control – Oculomotility
- Signs/Symptoms of Poor Eye Movement Control:
- Focusing Ability – Accommodation
- Signs/Symptoms of Focusing Difficulties:
- Eye Teaming Ability – Binocularity and Vergence
- Signs/Symptoms of Poor Eye Teaming:
- Vision Perception
- Signs/Symptoms of poor visual form perception:
- Visual Spatial Skills
- Visual Analysis Skills
- Visual Integration Skills
- Top 5 Visual Processing Skills that are Good Predictors of Reading Achievement:
- Reversals and Dyslexia
- Laterality/Directionality – Important Visual Spatial Skills in Reading
- So What is Dyslexia?
- Dyslexia and Research
- Vision Therapy and Dyslexia
- What should you do if you suspect a child of having dyslexia?
Though optometrists do not directly treat reading and learning disabilities, optometrists that specialize in neuro-optometry (developmental optometry/behavioral optometry) can correct visual problems that could potentially interfere or that are interfering with reading and learning. Vision problems play a significant role in the etiology of some learning disorders and can contribute to some of the difficulties associated with them.
80% children who are reading disabled have difficulties with one or more basic visual skills, but most of them have no difficulty with seeing 20/20.
The visual system is a significant part of how we process information and a key factor in how we learn. Most of what you perceive, comprehend and remember depends on the efficiency of the visual system. In the classroom, it is estimated that 85% of classroom learning comes through the visual system.
The visual process is learned. We do not even see clearly when we are first born. It is so complicated and so pervasive throughout the brain that any disturbances or erratic development in the 35 brain areas primarily or totally involved with the processing of visual information and any of the more than 350 intra-neural connections BETWEEN the 35 brain areas can cause inefficiency. This will have an effect on visual comfort, visual input skills, visual information processing, and sensory integration.
Fortunately, we can train how to use the visual system more efficiently and automatically by building new neural pathways (more dendrites!) at any age. The challenge is school demands are much greater the farther we go. Older children may not be able to compensate for an inefficient visual system once the academic demands increase. They begin falling behind in school, struggle with low self-esteem and have built in avoidance or inefficient strategies that need to be “unlearned.” It is no wonder that juvenile delinquent population are statistically shown to exhibit a greater amount of vision problems than the average population.
In one long term study of 160,000 school children in Texas, only 20% of children entering school had clinically significant vision problems. By the middle of second grade, 40% showed clinically significant vision problems. By the end of fifth grade, 80% of these children had clinically significant vision problems.
Identifying children before they start school, or shortly thereafter, allows us to help them build a solid foundation so that they are working at their potential so when the demands of school increase, they will be visually ready to handle the load.
Visual Input Skills Important to Reading
The ability to quickly and accurately move both eyes from place to place as well as smoothly track an object. Both saccades and pursuits are important when reading.
- Use of a finger or marker when reading
- Loss of place when reading
- Difficulty copying from the board
- Skipping or repeating words
- Head movement side to side while reading
- Difficulty in sports
The ability to make objects clear rapidly and automatically, regardless of the working distance to make targets clear. This is influenced by refractive status (nearsightedness, farsightedness, astigmatism), but you can have problems focusing without the need to wear glasses. Activities such as reading and writing require the ability to sustain and maintain prolonged focus up close. Copying from one place to another requires a change in accommodative focus that is rapid and efficient. Visual focus is also intimately related to the ability to sustain visual attention.
- Excessive time completing assignments
- Excessive time copying from the board
- Avoiding close work
- Blurring of print
- Eyes “hurt” or “tired”
- Reduction of comprehension when reading
- Reading slowly
- Short attention span
- Vocalizes when reading “silently”
The ability to use both eyes together smoothly, equally, simultaneously and accurately in order to keep objects single. This ability is intimately related to eye movement control and focusing ability.
- Double vision
- Words moving around on a page
- Motion Sickness
- Difficulty catching/hitting a ball
- Decreased depth perception
- Inefficient eye-hand or eye-body coordination
- Short attention span for near work
- Closing or covering of one eye
- Excessive blinking
- Holding a book too close
- Poor handwriting
- Reduced reading comprehension
70% of children with reading disabilities have visual perceptual deficits and it has been shown to be a good predictor of reading achievement. Visual perception, or visual information processing, is the process of gathering visual information, integrating this information with other senses, then comparing this information with past experiences, thereby, developing schemes to derive meaning in order to direct action.
- Frustration with letter and word recognition
- Poor letter formation and spacing
- Avoidance of written work
- Poor motor coordination
- Poor reading comprehension
- Confuses letters or words
- Reads slowly
Visual perceptual processing can be broken into the following three components that work together or build upon each other:
- Visual Spatial Skills
- Visual Analysis Skills
- Visual Integration Skills
Visual spatial skills are the skills used to understand directional concepts to organize visual space internally, then project body coordinates externally. This is important for reading achievement as well as mathematics.
Children with reading problems make more spacing, visual-motor mistakes, reversals of letters, sequences and words when reading, spelling and writing and make more transposition errors compared to average readers.
Visual analysis skills build logical thinking and used to identify, sort, organize, store and recall pertinent visually presented information. It is the ability to take in visual information, remember it and apply it later. These abilities are essential for quick and accurate identification and discrimination of objects, comparing similarities and differences, recognizing and generalizing forms, and coming to valid conclusions based on the accurate analysis of available visual information.
Visual memory and visual discrimination have the largest association with reading ability than other visual analysis skills. Both sequential and spatial visual memory is important in the storage of orthographic information which no only affects reading, but also spelling.
Visual Integration skills allow you to integrate information with your other senses or with other visual information. Two areas of visual integration skills significant to academic success is visual motor integration and visual-auditory integration.
Visual motor integration consists of coordinating visual perceptual skills together with gross-motor movement and fine-motor movement. It is the ability to integrate visual input with motor input. This is how we plan, execute and monitor motor tasks.
Visual-auditory integration requires linking together visual information with information heard. Although vision becomes are dominant sense, good auditory skills are necessary in order to achieve good vision.
- Visual Memory
- Visual Discrimination
- Visual-Motor Integration
- Visual-Auditory Integration
Oculomotor skills, accommodation, vergence, binocularity and visual perceptual skills are just some of the aspects of vision that have been found to statistically impact learning, but most especially reading.
Remember, visual perceptual deficits does not just influence reading. It can influence other academic areas such as fine-motor coordination (graphomotor), spelling, memory, visualization, speed of information processing and mathematics.
The prevalence of dyslexia has been estimated to be 10-20% of children in a regular classroom and greater than 50% in a special education classroom.
When you hear the word dyslexia, many people immediately visualize an image of jumbled words printed in reverse. This word reversal phenomenon is certainly true for some dyslexics, however dyslexia is far more complicated than simple word reversals.
Reversal problems in children older than eight years old indicate problems with vision perception and can be remediated.
Neurological development and, therefore, vision development is based on movement. For example, creeping (mobility on hands and knees) is one of the most important movement patterns to help vision development. It is through creeping that the vestibular (balance), proprioceptive (feel) and visual systems combine to operate together for the first time. Laterality is the result of this integration, which is a cooperation between both sides of the brain.
Motor competence is a necessary precursor for visual attention. Without integration between the senses (vestibular, proprioceptive, vision), there would be no sense of balance, space and depth. Lack of integration affects body control, attention, eye-hand coordination, focusing, eye-teaming, visual perception, sequencing, organization and academic skills such as reading, writing and math.
Laterality is an internal self awareness of two body sides and knowing they are different. It requires good balance, vestibular function and an awareness of a body midline (an invisible line that divides your body in half). During a study at the Southern California College of Optometry, 74% of children already determined to have a learning disability failed tests used to assess laterality and directionality.
Some behaviors observed in kids that have not developed laterality when writing are switching hands so they do no cross the midline of their body, motor overflow, rotating the body so as not to cross the midline, not using the nondominant hand for paper support.
These tendencies happen in all young kids, but if confusion with laterality occurs after 8 years old, it can potentially cause problems.
Laterality eventually evolves into directionality. A person must understand laterality on their person before it can be applied in space. This means if you do not know the two sides of your body (left and right), how can you know what to call the two sides of the room? We always learn how to judge where things are by first learning how to relate it to ourselves. When you start applying left and right concepts to your external visual space, you are beginning to learn directionality.
Directionality incorporates up, down, ahead, behind, and any combination thereof into the equation. It also means projecting these directions including left and right out into space. Again, a person must understand these concepts as they relate to themselves before they can apply them to other things.
Directionality is very important in decoding letters. If you don’t have this concept down, learning to read can be very confusing. For example, the letters “b,” “d,” “p,” and “q,” all look like the same symbol if you do not have any concept of orientation. Research has shown that children who still have reversal problems after age 8 will likely have problems developing good reading skills.
Dyslexia is a difficult term to define, especially since it has become the catch all word for many types of reading and processing problems. Dyslexia, in general terms, is a learning disability that makes written language more challenging. People with dyslexia have trouble mostly with reading, writing and spelling.
Dyslexia is generally believed to be a problem with interpretation of information by the brain; information taken in is not processed in standard ways. Words may be read but not understood, or letters rather than the entire word are seen or read.
Those that suffer with dyslexia are a population of children who have difficulty learning to read in spite of good intelligence, educational opportunities, cultural experiences and normal sensory development.
Dyslexia should be diagnosed only after other causes for reading difficulties are ruled out, such as vision, hearing or instruction problems.
Unfortunately, many schools districts around the country, dyslexia is often diagnosed and used to qualify a student for special education if a student is two years behind or more in reading and not working up to their intellectual potential.
Neuropsychologists most often conclude that dyslexia is a language processing problem. Brain image studies (fMRI, PET scan) show that people with dyslexia seem to process language information in a different area of the brain than people who do not have dyslexia, regardless of intellectual ability.
When comparing good readers with poor readers, other brain image studies have shown that non-efficient readers use predominantly the speech/auditory parts of the brain while efficient readers use the visual parts of the brain.
Though the brain image studies is an exciting way to understand the differences in how the brain fires in different types of learners, it is important to understand what comes first. Does the brain process a certain way during reading because it did not learn and develop the skills needed efficiently or is there something physically wrong with the brain that caused the person to process differently?
Many researchers and special educators believe that there is neurological deficit that causes dyslexia. The brain is dysfunctional and different learning methods need to be used, in order for learning to occur. However, it has been shown with EEG studies that the way a brain processes can be changed with proper feedback to the brain. Occupational therapy, physical therapy, speech/auditory therapy and vision therapy would not be successful if we could not re-pattern the brain.
A prominent Behavioral Optometrist, Steven Ingersoll, uses the analogy of running. If you observed hundreds of runners, you would see that they all perspire. Some sweat more than others, but indeed, all of them sweat. Every device used to monitor sweating comes back positive. Brain imaging shows that, indeed, when running, the part of the brain that directs sweating is indeed stimulated, but when you aren’t running you don’t sweat the same. Research can then conclude that sweating causes running. Sound absurd? Yet, if you learn a compensatory way to read that is not efficient and therefore different parts of the brain are used when reading, it is concluded that since the parts of the brain that SHOULD be used when reading are not stimulated, they must be broken or dysfunctional.
Learning to read requires both phonetic and eidetic processes, which are cognitive ways to decode and encode words, respectively. Visual skill deficits can interfere with both encoding and decoding words, in a host of different ways. Vision problems can cause problems with sight recognition, reading comprehension, memorization, recall, fluency, speed, rhythm and the length of time spent reading or writing.
Since vision is such an integral part of the way we learn and process information, children who have difficulty in reading and/or who are poor spellers may have coding problems and should receive a thorough optometric exam by a specialist in the field to rule out poor visual skills in all areas of vision function including input, processing, storing, retrieval and output.
According to research, it is clear that some individuals already labeled dyslexic, reading or learning disabled, as well as children experiencing academic difficulties can benefit from optometric intervention, such as vision therapy. Optometric intervention before beginning or in conjunction with dyslexia reading programs will help facilitate the learning process and ensure the individual in getting the most out of these programs.