How Does Vision Affect Learning?

Published May 24, 2020

Vision is critical to learning

Since 75 to 90 percent of all a child learns is derived 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.

These are the visual skills needed for reading:

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 — approximately 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 normal.

Binocular coordination: Eye tracking and 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”).


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.

Commonly, a child loses his place while reading and/or uses their finger or a marker to maintain his place. While making the eye movements during the act of reading, the child might not land on the next word, but rather land a few words further on. Consequently, they commonly omit small words or confuses small words. Often, a child just adds a word or two to make the sentence make sense.

Double vision or overlapping vision (Figure #1) 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.

Figure #1


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.


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.


Directionality is another visual skill important for academic success. One test for this skill is illustrated in Figure #5. Look at Figure #2 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 reflex.

Figure 2

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 #3. 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 together.

Figure 3

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 #4. It is easy to see the difference in reading for meaning when the span of perception is wide.

Figure 4


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 skill.

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