For the Parents Trying to Reverse Their Children's MyopiaIntro
First of all, condolence to the parents who are dealing with children, who either refuse to wear reading glasses or, if they do, read further within their far point.
Why are they reading further within their far point? Well, they can't see well. Children are accustomed to seeing things clearly and the experience of utter blur is just unacceptable for them. But why do they find blur unacceptable?
And why are they refusing to wear plus? Probably they are just lazy - they hate to have to work. Or is it because they don't feel good with it?Case study: A 20/20 child
A brilliant child is doing well in school, and we want to help him avoid myopia. We reason that he can read comfortably at 40cm. So we give him a pair of eyeglasses of +2.5D to do it.
Then what happens? He puts on the glasses and feels an immediate tension in the frontal part of his eyes. He feels uncomfortable and scared and automatically lean closer to see - usually much closer than needed.
Although the prescription is optically correct. At 40cm he might still be experiencing close strain. In addition, the plus lens induces a kind of tension forcing ciliary relaxation - a tension whose intensity is determined by the strength of the plus lens in question.
(and he gets red eyes, that could very well be a benign symptom of the radial components of ciliary muscle doing its job)
There are at least two problems here:Problem 1: Why children lean so close to an viewing object?
As children develop, some of them will remain emmetropic throughout their lives; others might become myopic. There is actually a rarely-explored key difference between the prospective emmetropic child and the prospective myopic child. Namely, that the prospective myope might just not
know how to leverage his focusing ability to minimize blur. Instead, he would use peripheral vision to look at everything - And of course he would need to lean closer than needed to see well.
What happens next? The child believes that he is myopic and the parents bring him to see an eye doctor. The child then looks at the Snellen chart, as a whole
, and concludes that he can't see well. He then gets his first minus lens.In many of those first eye exams, if only the child focuses on each letter on the Snellen, instead of focusing on the Snellen as a whole, there's a possibility that the child can actually read all the letters on the chart.
Another question arises. Why then do those children choose to use peripheral vision instead? One speculation in the literature is that their central vision is not fully developed yet (since in child development, peripheral vision comes first and central vision comes much later). If that's the case, then it's probably a very bad idea to teach a young child to read, before they even learn to focus properly. In some cases, when one acquires efficient focusing skill, they might realize in retrospect that part of their myopia is really just attention-related issues.Problem 2: Plus lens induces too much strain
One thing that can be done is to increase the diopter of reading glasses by an increment of +0.5. We can start with +0.5, ask him how he feels about it, and wait a few days. Once the tension becomes manageable, we can give him a +1D. And then once more with +1.5D. Some children have less tolerance with +2D. However.
As with any person, a child can be conditioned to embrace the blur too. For example, he might initially complain about the +0.5D prescription, but he might just get used to it after a week or so. It's important to eliminate that fear of blur, because once he does, he will know that he doesn't need to approach an object awfully close to see it clearly. The underlying theme is that blur clearing is only healthy and necessary, and that children can be conditioned to enjoy doing it.
All in all, we are better off administering weaker plus lens to children and have them read as far away as possible
. Reading too close, even if beyond the far point, could induce proximal accommodation (as shown in the studies of microscopists), which in turn leads to more close strain.Adjusted Plus Lens
Plus-lens-induced strain is also in part due to accommodation-convergence disturbance and oculomotor imbalance. To remedy this situation, one can use a plus prescription of ~1.5D with a weak base-in prism (to minimize the exophoric effect of convex lenses), or lessen
the pupillary distance of the prescription to attain a similar amount of prismatic effect.Fundamental changes in habit
Children play with what is available to them. If we have smartphone or iPad at home, they will probably become easily addicted to it. And if they can find dolls or legos, they will probably stick to them too.
Back then when computers were not commercially available, children still find ways to entertain themselves - mostly outside. Actually, if there were no
addictive toy or gadget in the house, they'll most likely get addicted playing outside. Why not bring them to the parks, or let them play with non-agressive animals?
Besides,we can read the stories to our children, instead of having them read the stories themselves. Just like the adults, addiction is very hard to eliminate, hence a more sustainable approach would be to prevent the addiction in the first place. Don't just stop them from doing something, lure
them into the activities that promote distance viewing. Summary
a) Teach our children how to focus, if applicable.
b) Increase the strength of reading glasses incrementally, but keep the strength relatively low, and the viewing distance relatively far.
c) Consider using a plus lens with base-in prismatic effect.
d) Avoid living in a near environment is still the best shot. Lure the children into entertaining distance activities.