Vision & Reading
The following are excerpts from an article on Vision, Learning and Nutrition
by Donald J. Getz, OD, FCOVD, FAAO
This article by an eye doctor discusses children's problems with reading, learning, and behavior caused by convergence insufficiency, eye tracking problems, eyes and esophoria, eyes and exophoria, and other visual problems.
Vision and 20/20 Eyesight
Eyesight is simply the ability to see something clearly, the so-called 20/20
eyesight (as measured in a standard eye examination with a Snellen chart). Vision goes beyond eyesight and can best be defined as the
understanding of what is seen. Vision involves the ability to take incoming
visual information, process that information and obtain meaning from it.
Two general statements can be made about vision. First, vision is learned. A child learns to see just like he learns to walk and talk. When learning to walk and talk, he has the added opportunity of imitating his parents and siblings. In addition, parents can observe their children to determine if walking and talking are developing properly. Vision development, however, generally proceeds without much concerned awareness on the part of parents. Because of these differences in development, no two people see exactly alike.
Vision Is Learned
Vision is learned; therefore vision is trainable. If a child
does not possess the necessary visual skills, he can be taught to possess them
through the proper Vision Therapy techniques.
Adequate Vision Is Critical to Learning
Since something like 75% to 90% of all a child learns comes to him via the
visual pathways, it stands to reason that if there is any interference in those
pathways, a child will not develop to his maximum potential.
The Visual Skills Needed for Academic Success
Visual Acuity: There are many visual skills which are important for academic success. One of
the least important skills is termed visual acuity (clarity, sharpness). This is the so-called 20/20,
20/400, etc., eyesight. All that is meant by the notation 20/20 is that a person
is capable of seeing clearly at a distance of twenty feet. Unfortunately, how
well a child sees at twenty feet has little to do with how his vision functions
at the reading and learning distance -- aproximately eleven to sixteen inches from the face. In fact, it is my opinion that the Snellen eye chart test which measures
visual acuity actually does more harm than good. It gives both parents and
teachers a false sense of security that vision is normal. There are many other
important visual skills that might not be developed even though visual acuity at distance is
Binocular Coordination - Eye Tracking - Eye Teaming: One of the more important visual skills is the ability to coordinate the two eyes
together. A child is born with two eyes, but he must learn to use the eyes as a team (eye teaming). Some children learn to do this properly while others do not. For
example, some children develop a problem known as exophoria, which is a tendency
for the eyes to deviate in an outward direction. This is not the same as a
condition known as exotropia where the eye actually can be seen to be in an
outward position (turning outward, eye turn, “wall eye”).
Adequate Convergence: During the act of reading, the demand is for the two eyes to turn inward so that
they are aimed at the reading task. If the eyes have a tendency to deviate
outward, the child must use excess effort and energy to maintain fixation on the
reading task. Most studies have shown that the greater the amount of effort
involved in reading, the lower will be the comprehension and the lower will be
the performance. When reading, the eyes do not move smoothly over a line of
print. Rather, they make a series of fixations looking from word to word. When
an exophoria exists, each time fixation is broken and moved to the next word, the
eyes will tend to deviate outwards and they must be brought back in to regain
fixation. Human nature being what it is, the child generally has an avoidance
reaction to the reading task. This is compounded by the fact that anything the
child doesn't do well, he would rather not do.
This is the child who looks out
the window rather than paying visual attention. He is commonly given labels. He
is often accused of having a short attention span and not trying. He is told
that he would do better if he tried harder, but he has tried harder to no avail.
He is often labeled as having ADD or ADHD, dyslexia, minimal brain dysfunction, learning
disability, etc. Commonly, he loses his place while reading and/or uses his
finger or a marker to maintain his place. While making the eye movements during
the act of reading, he might not land on the next word, but rather land a few
words further on. Consequently, he commonly omits small words or confuses small
words. Often, he just adds a word or two to make the sentence make sense. If the
two eyes are pointing at the same point in space, a person will see the fixated
object as being single. Double vision or overlapping vision (Figure #3) results
if the two eyes are not exactly pointing at the same point. Don't expect a child
to tell you that his vision isn't clear. He has no yardstick of comparison to
inform him that his vision differs from the vision of anyone else.
Astigmatism, Eye-Hand Coordination, Visual-Motor Problems and more: I have maintained for many years that I could walk into a classroom and pick out
those children with coordination type visual problems. They get into distorted
postures in an attempt to get one eye out of the act. They often put their head
down on their arm, cover one eye with their palm or rotate their head
so that the bridge of their nose interferes with the vision from one eye.
Esophoria: Another eye coordination problem is termed esophoria, which is a tendency for the
eyes to turn inwards. The educational implication of this particular problem is
that a child with esophoria sees things smaller than what they actually
are. In order to see an object properly, it is necessary to make the object
larger. The only means at the disposal of the child to make it larger is to
bring it closer. Eventually, the child is observed with his head buried in
a book and still not achieving.
Reading Skills and Binocular Visual Skills
One of the tests used in optometric offices is to have the child read words while
looking into an instrument called a Telebinocular. The performance is compared
between reading with either eye alone and with both eyes together. The difference
in performance is often quite dramatic if there is an eye teaming problem. One
eye performance might be quite satisfactory, but reading with both eyes together
will be slower and many more errors will be made.
Other Visual Skills
Directionality: Directionality is another visual skill important for academic success. One test
for this skill is illustrated in Figure #5. Look at Figure #5 and determine what
you see. If the visual reflex is from left to right, a duck will be seen.
However, if the visual reflex is from right to left, a rabbit will be seen. This
is just one test out of a series to determine the directionality of the visual
It is just a convention of our culture that the English language proceeds in a left to right direction. Other languages proceed in a right to left direction and still others have a vertical orientation. Many people feel that it would
make more sense if the language proceeded as illustrated in Figure #6. If a
child does not visually proceed from left to right, through Vision Therapy he can
be taught to develop this skill just like he can be taught to team his eyes
Form Perception: Form perception is another important visual skill for academic achievement. This
can best be illustrated by referring to Figure #7. The child is shown these
forms one at a time and he is simply asked to copy them. It is amazing to see
some of the distortions that a child will make in attempting to copy these forms.
If a child can't perceive and copy these simple geometric forms, it is
unreasonable to assume that he will be able to perceive the wiggly lines which
make up letters which in turn make up words, which in turn make up sentences
which stand for abstract ideas. We see children often who can't tell the
difference between a square and a rectangle or a circle and an oval. This is
also a skill which can be improved through Vision Therapy.
Attention Span/Span of Perception: The Span of Perception is also related to success in school. Many children see
just one word at a time with each eye fixation. Reading speed can be improved by learning to see two, three, or more words with each eye fixation. This could be compared to reading through a straw. This is illustrated in Figure #8. It is easy to see the difference in reading for meaning when the span of perception is
Visualization: The ultimate visual skill is visualization. This is similar to being able to see
things in the mind's eye. There are authorities that state that the ability to
visualize is very closely allied to the ability to think. In other words,
thinking is related to the ability to abstract from specifics and the ability to
visualize is deeply involved in this process. Visualization is also a trainable
There are many other visual skills that time and space do not permit me to
mention. However, it is hoped that the reader will realize from the above
discussion that there is a lot more to vision than just 20/20.
Nutrition and Vision
When I see a child with a learning problem, I feel very strongly that there
usually is more than just a single cause. For example, when I find a visual
problem, if I probe a bit further, a nutritional problem will be found as well.
Children often walk into the office eating a candy bar or sipping on a cola or
other soft drink. When they are asked what they had for breakfast, the response
usually falls in the frosted, sugary flake category or the answer is that they
had no breakfast at all.
When I am asked which nutrients are important for optimum visual functioning, I
respond that the same nutrients essential for the rest of the body are the ones
needed for vision. This is because vision does not operate independently of
the rest of the body.
In all cases, a diet of high quality, nutrition-rich, unprocessed foods is important if we are
going to be successful in Vision Therapy. Vision therapy involves a learning process
and, as with any learning process, learning will be maximized if a healthy body
and a healthy mind are brought to the learning task.
Reprinted with permission from The Journal of Applied Nutrition Volume 28,
This complete article may be purchased by writing to College of
Optometrists in Vision Development, 243 N. Lindbergh Blvd., Ste. 310, St. Louis, MO 63141-7851 and requesting the article: Getz, Donald J., O.D., "Vision and Perception Therapy," 1973.
Feingold, Ben F., M.D., Why Your Child Is Hyperactive, Random House, New York,
Lane, Benjamin. O.D., "Myopia," 1976. College of Optometrists in Vision
Ludlam, William, O.D., "Visual Evoked Response," 1974. College of Optometrists
in Vision Development
McDonald, Lawrence W., O.D., "Visual Training," 1962-1963. Optometric Extension
Ott, John. Sc.D., Health and Light, The Effects of Natural and Artificial Light
on Man and Other Living Things, Devin-Adair Co., 1973.
Skeffington, A.M., O.D., Continuous writings, Optometric Extension Program
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