A good vision is not only seeing 20/20

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Just as “seeing” is not the same as “looking”, talking about vision it is not only enough that light focuses in a specific point of the retina in order to see 20/20, but also, vision is understanding what we see.

In order to understand this concept, I will firstly explain what the words Visual Acuity mean, that many times we utilize them with our patients when we say “You have 20/20 vision“, but maybe you are not quite sure what actually that means.

When we assess the Visual Acuity test, we are assessing the ability that someone has to identify some letters or patterns from a distance where they should be seen; and the final value is the smallest symbol size than the patient is able to read from that distance.

Let me explain it better: when we perform this test, the patient must sit down 20 feet (6 meters) away from the letters chart. When we say that a person have 20/20 visual acuity (100%, 1.0 or 6/6, everything is the same), what we mean is that the person sees 20 feet away from the chart what she should actually see 20 feet away. But for instance, if that person has 20/10 visual acuity (6/3 or 0.5), that means she would only see from 20 feet what she should see from 10 feet, that is, she has 50% of vision.



Therefore, Visual Acuity is the ability to see the details of an object. But precisely because that object is not floating in the void, but furthermore, there are many more objects surrounding it, we are in a distance from that object, we may want to execute an action with it and other senses may be implicated in this action…, vision is just not only clearly seeing that object, but that many more “visual qualities” might be implicated, as we saw in a previous post .


“It is estimated that as much as 80 percent of all learning during a child’s first 12 years comes through vision”.

Because a child or an adult has 20/20 visual acuity according to a certain test, it does not mean she has good vision, since she may have problems in order to focus on a text when she reads a book, or may have bad eye-hand coordination and consequently have a bad writing, or may have some problems to how her eyes work as a team and they feel tired 10 minutes after they start a near task, or may be "clumsy" and hit herself with things because she does not calculate the distances well. In all of these examples, vision is involved and with them I only wanted to show that although we have a 20/20 Visual Acuity maybe we do not have a 100% Vision.

In many optician’s, when a person goes to check her vision, they only obtain this result and only find out the lens required to improve that percentage (whether there is myopia, hypermetropia or astigmatism), without assessing if that vision works well and if it works along with the other senses. That is, for them the goal is to obtain 20/20 visual acuity and they do not think in any other symptom that shows that it is not only important to improve Visual Acuity, but also to improve the performance working at near, or practicing a sport or reading and its comprehension. For it, as the daily problems are not always related to a visual problem, I recommend you to go to a specialized office that offers you a broader eye examination. You would be surprised of how many symptoms and problems at school can be removed by using Visual Therapy, and what this can be done to improve the quality of life in general of any person.

A child may be diagnosed with a “perfect vision” by an optician or an ophthalmologist (it doesn’t matter) simply because she has 20/20 visual acuity, but without being assessed the necessary visual skills (focusing, peripheral vision, eye-hand coordination, discrimination of shapes, spatial relations,…) required to have a correct learning or a good physical coordination. In a later post I will thoroughly explain the visual problems related with learning.


If a child is struggling with academics, sports or home behavior, parents and teachers should be encouraged to consider that a vision problem may exist, beyond a Visual Acuity.


A simple comparative example is the following one: when we read, it is not enough to verbalize what we see written and to read as a parrot, we have to understand what we see. Therefore, when we read, we must not only clearly see the letters, but we have to know, to remember, to interpret and verbalize what is written; vision process is responsible for all this.


So, after all this, mi goal is for you to have a clear understanding that when you go to an office or optician’s, the Visual Acuity assessment must be ONLY a value obtained of the whole visual examination in order to achieve a precise diagnosis.



BOOK: "20/20 is not enough"

What is VISION? Its importance.

Enlace a entrada en español



As many people know, VISION is one of the five traditional senses. Nowadays, some people include in this group the balance and the proprioception too; I will calmly explain these terms later on.


Vision is the most important sense because up to 80 percent of the information that we receive, gets in across the eyes; not only the images but all the feelings that come with them too. That is why, it is very important that the visual system is effective, because it affects the learning and even the behaviour. In the reading case, up to 100 percent of the information that gets in, is purely visual.


People usually technically define VISION as “Action, effect and ability to see”. But personally, this definition does not satisfy me.


Vision does not occur only in the eyes. The eyes are just the most external part of a “complex mechanism”. They are the entrance. They are just responsible for receiving the object’s image; it is a very important function, but we do not see just because of them. Later on this image and all the information about it, follow a process until the brain is reached, and there we process, identify, understand, memorize, remember, learn and answer all the information that we receive. All that is VISION. Thereby, it is not only important that the image gets in but also knowing what to do with it. And that is what separates us from the animals; they receive an image that goes to the primitive brain but they do not learn from, memorize, understand, interpret it... The thinking part is what makes us different. And this is achieved by the NEOCORTEX (the “wrinkled dough of the brain”).


Thereby, in order for vision to be perfect, it is required for the COMPLETE visual path (not only the eyes) to be in perfect condition.

Vision is not efficient if:
- any of the eye’s layers prevent the light from getting in, that is, they lose their transparency;
- the light is not transmitted from neuron to neuron from the first layer of nervous cells which is inside the eye (which is known as the retina, the layer that receives the luminous stimulus), as far as the last neuron of the brain (in many areas of it, not only in the purely visual one);
- or there is some injury in any part of the visual path.

In another post I will explain the steps that occur in the Visual Process and that the vision does not just mean seeing 20/20.


It is crucial to have a good vision for the general development of a person’s life, and it is the most important tool for a child to have success at school. If the vision fails, the child’s school performance or the adult’s work performance fails too. Take one moment to think how many visual activities we do every day: at school or at work: reading, writing, drawing, painting, building, calculating, having contact with other people, fixing some things, cutting hair, putting bricks,… And during the rest of the day: when we take the right bus, drive, walk the street, eat, cook,…
Constantly, we are receiving visual information from which experiences are created. They can be better or worse depending on the quality of the information that we receive.

Nowadays, in Spain, the Optics-Optometrist National Association (Colegio Nacional de Ópticos-Optometristas –CNOO-) and in USA, the College of Optometrists in Vision Development (COVD) estimate that:
- up to 25 percent of the schoolchildren may have visual problems not diagnosed, that can affect their ability to learn (COVD) (CNOO)
- up to 70 percent of schoolchildren who have a learning disability in reading have some sort of visual problem; (COVD)
- and around 30 percent of school failure is related to visual upsets. (CNOO)


One child thinks everybody sees the same way as him; so, if he sees wrong, he will say nothing because he will think that it is usual. Therefore, the parents and teachers are the ones who have to suspect or recognize whether a child has some visual problem. The discovery and early treatment, before or during school-age, can avoid some future academic, emotional and social problems in the child. In future posts I will give a list of some signs and symptoms of visual problems that may indicate the need for a comprehensive vision exam, that I hope it serves you as an orientation.


When we are born, the vision is not a sense totally developed; so, everybody has to “learn to see”, just like we learn to walk. We have to learn to interpret the visual information that we receive. And just as the child’s motor development happens step by step while growing, the same happens with the vision. Both developments happen in parallel. So, if the child skips any motor development phase, it can affect the visual development, thus causing lazy eye, strabismus, or learning disabilities.


“We do not see with the eyes, but through the eyes” (Larry McDonald O.D.)