Does Reading Cause Myopia?

With some help from AC/DC, let's find out . . . .

Some people believe that reading causes myopia. Some people also believe that the earth is flat.  Okay, maybe that wasn't too nice, and if I've offended anyone from the Flat Earth Society, then I sincerely apologize.

Personally, I don't understand how people can believe that reading causes myopia. If this were the case, then every person who has ever learned how to read would be myopic, and this isn't the case; there are plenty of avid readers out there that have excellent vision. And what about children who become myopic long before they've learned how to read? If reading causes myopia, and a child becomes myopic without ever knowing how to read, then where did the myopia come from? Because of these two groups -- avid readers with excellent vision and myopic children who don't know how to read -- I believe that the "reading causes myopia" theory must necessarily be tossed out the proverbial window.

Well, if reading doesn't cause myopia, then why do so many children become myopic during their formative years in school? Why are there numerous new cases of myopia in school children generally between the ages of 7 and 13? And why does this number drop off for young adults with the exception of college students or those who enter intensive near-work environments? Can't we conclude that reading or at least near-work causes myopia? Again, I believe the answer is no. And here's the key -- it's not the reading or the near-work itself that causes the myopia, but instead it's what the body is doing while the person is reading or while they're engaged in near-work that potentially leads to myopia. To better understand this, let�s talk a moment about stress.

There are many different types of stress, but all these result from the same exact thing: imbalance. In the physical world, for example, stress is defined as the force per unit area within a given material. When a team of engineers build a bridge, they have to determine the amount of force that will be applied to a given area. How will the forces change when the material is heated or cooled? What kind of deformation results when the bridge is weighed down with cars and trucks? What is the direction of the applied force? And how does the material respond when the force is removed?

In another sense, physical and/or mental stress result when a person is in disequilibrium. When something is �weighing on your mind�, in a very real sense, a force is being applied to your thoughts and the result is imbalance or stress.

In phonetics, when emphasis is placed on a given word or syllable, it sounds LOUDER because that part of speech is being stressed. When speaking, this imbalance or stress can make a big difference. In Spanish, for example, a speaker may say PApa or paPA. In the second case, paPA means dad or father. In the first case, however, PApa means potato. So, with one small difference in syllabic stress, you could be calling your father a potato without even knowing it! Simply put, stress is describing a state of imbalance or incongruence.

The human body is truly amazing, and it is designed to handle large amounts of stress for short periods of time. Problems arise, however, when a relatively small amount of stress is applied to the body over long periods of time. The Theory of Biomechanical Congruency states that when a body is at rest, there should be no stress on any part of the system. When the body becomes incongruent or unbalanced because of stress, however, a warning light comes on. Again, if the imbalance or stress is removed after a relatively short amount of time, then congruency and equilibrium are restored to the system. On the other hand, if the stress is not removed, especially over long periods of time, then the integrity of the system may be compromised and lasting harm may result.

So, how does this all relate to reading and near-work? As I said before, I don�t believe that reading or near-work in themselves lead to myopia. The problem is what the body is doing while engaged in near-work activities. Here�s the secret: most reading and most near-work is where? Down here!

Let�s take a look at reading. When you�re reading a book, where is it normally? Down here. While you�re reading, what does the body do? It becomes stressed and imbalanced. Your head and neck bend down. This leads to the shoulders and upper back assuming a hunched position. When the upper back and shoulders are hunched, then quite naturally the lower back becomes bent. When the back is bent, then stress is created in the hips and legs. Stress in the back creates pull on the stomach and diaphragm which leads to an almost automatic shortness of breath. In reality, reading is one of the most taxing and stressful things we can do to our bodies. So, is the answer to stop reading all together? No. There is no problem with reading as long as the physical stress placed on the body while reading is alleviated and removed from time to time. Reading should be balanced with relaxation.

Avid readers who maintain their good vision also maintain their sense of congruency, even while reading. They may bend over their material, but their hunching does not become habitual. Myopes, however, hunch to the point of habit. What we do today will become easier to do tomorrow, and if straightened stature is replaced by poor posture, then myopia has a much greater risk of setting in.

Consider electricity for a moment. In the flow of electric charges, there is something called alternating current or AC. Unlike direct current (DC), alternating current reverses itself periodically. Beginning at zero, the flow of electricity grows to a maximum, and then it decreases to zero. At that point, it reverses itself and then reaches a maximum in the opposite direction. Once again, it returns back to zero, and repeats this cycle indefinitely. The time it takes to complete one cycle is called the period, the number of cycles per second is called the frequency, and the maximum value in either direction is known as the current's amplitude.

When it comes to reading, myopes get locked into �direct current�, and their flow is in one direction only � toward stress. They bend or hunch over their work much more than do emmetropes. Their heads and necks bend down farther � greater amplitude � than emmetropes. And the myope never takes the time to reverse this flow. Avid readers with good vision, however, get into the habit of �alternating current.� First, they have a smaller amplitude � they don�t hunch quite so much over their work. Next, after their flow has been toward stress for a time, they reverse it toward relaxation. Also, the cycle is short and the frequency is high � their reading blocks are short and they take frequent breaks to stand up, stretch their heads, necks, shoulders and backs, and then they go back to work. The difference is that their physical stress does not become habitual.

Remember, habitual physical stress leads to a change in the shape of the resting body � it�s no longer as straight as it could be. When the neck is bent forward, even slightly, stress results in the neck, jaw, and shoulders. When this becomes habitual, then the muscles in those parts of the body become habitually shortened. And when this happens, the resulting pull ultimately creates visual distortion in the eyeballs via the facial muscles. The key is to make physical and mental congruency (relaxation) the overriding habit in all activities. And if you find yourself in a stressful situation, that�s okay, as long as you �reverse the current� and spend time bending your body back into it�s naturally straight position of good posture.

So, to recap, does reading cause myopia?  No!  It�s not the reading itself but instead the poor physical posture your body adopts while reading that creates the biggest problem. Stay tuned for specific strategies for �reversing the current� and for making biomechanical congruency your new habit.