|We often see children reading like this -- and nothing is said or done. Further, the standard medical statement is that long-term reading at -6 diopters has NO EFFECT on the refractive STATE of the eye. Tragically, the experimenal data demonstrates that reading at this distance has a profound effect on the natural eye's status.. (See the effect of "open" and "canged" environments on the natural eye's refraction as presented below.)
It is indeed very difficult to STOP a child from doing this type of writing. If a doctor makes the statement that nearsightedness can not be prevented BECAUSE you can not stop a child from reading at 6 inches (-6 diopters) -- then the statement would be correct. The child must learn to "modify" his reading habits -- as the first step in preventing the development of nearsightedness. When monkeys are placed in this type of situation, their focal status WILL MOVE in a negative direction.
But the reality is that if you can stop a child from doing this -- and get him to use a proper-strength postive lens, then nearsightedness can be prevented. Obviously this is not easy, and requires understanding and resolve to make prevention effective -- in the long run. A great deal of responsibility must rest with you if any optometrist is going to assist you with prevention at the threshold (20/40 to 20/70) level of nearsighedness.
It is easy to discuss prevention -- but hard to implement. This is often because of our resistance to any fundamental change in our personal habits. Ultimately we must understand the consequence of this bad habit of ours.