There is controversy over the exact relationship between vision and learning. For example there is a negative correlation between distance refractive error and reading ability. Myopic or nearsighted children who cannot see clearly at a distance without glasses are more commonly good readers. Children who spend tremendous amounts of time reading become nearsighted. Before Alaska became a state myopia was rare. After becoming a state, more than 50 percent of the children in Alaska developed nearsightedness. Thus, correlation is such that nearsightedness or poor distance vision is highly correlated with success in reading. Restated another way, poor distance vision is associated with better reading abilities. Farsighted children statistically are poorer readers than myopic children.
Some of the mechanical visual skills which are related to reading include focusing or accommodation, and eye teaming, or convergence. Fatigue of one or both of these systems may interfere with reading. There is also a relationship between eye movements such as saccades (whereby we change fixation from one target to the next) and smooth following movements known as pursuits and reading. Children who cannot make accurate eye movements are often found to skip lines and words while reading.
The visual system was originally designed so that the peripheral vision was responsive to motion detection (danger from the jungles) with a central portion for fine discrimination (to identify the source of danger; e.g., a lion.) In the school environment the child is expected to ignore the peripheral portion of their visual system and pay attention with the central portion. If the child can not ignore the peripheral portion, he/she becomes distracted. Improvement in eye movement skills often results in less distraction and fewer errors of skipping words while reading.
Reading requires very accurate saccadics, which are fixations from one spot to another. Children who have poor eye movements are easily distracted and lose their place. Remember, the eye movement system was designed so that peripheral vision detects motion and danger. Imagine what happens when the system works correctly in the class room. As soon as there is peripheral movement, the eyes move toward the source of movement. This results in the complaint of inattention. Thus, reflexive eye movement skills must be socialized so that they do not respond reflexively to peripheral information. In addition, speed and accuracy must be trained so that one does not lose one’s place.
The skills are easily improvable with vision therapy. Once the information is brought into the eyes, it must be sent back to the brain for appropriate processing. The information must be utilized and integrated with the sensory and motor areas of the brain. Defects in the perceptual (interpretation of visual system) and motor (the integration with output, e.g., hand-eye coordination) may interfere with the reading process. Perceptual motor skills are key in the early acquisition of reading skills. A deficit is important to identify very early on-- i.e., five to seven years of age. Remediation of the skills at a later date, such as age 12, will be less effective for reading. Thus, early identification and treatment is essential. It is evident that there is more to good vision than 20/20.
It has been presumed that children who reverse letters or words see them backwards. This is false. They have directional confusion. In the real world direction has no meaning. For example, a chair is a chair no matter which way it is placed. Changing direction does not change interpretation. In the world of language direction changes meaning. Connect the bottom of a chair and it looks like a "b". Turn it 180 degrees it becomes a "d", flip it upside down and it becomes a "q" and flip it again it becomes a "p". Thus, direction changes meaning. The difference between "was" and "saw" is direction.
As mentioned previously, we should correct all optical errors of the eyes (glasses); eliminate eye muscle problems; and create smooth accurate eye movements. In addition, we should make sure that we properly interpret what we see and use it appropriately. These are known collectively as perceptual skills and include form perception, size and shape recognition, visual memory, and visual motor integration (hand-eye coordination.)
