HOW TO SAVE YOUR CHILD'S VISION
What about adults? The preventive techniques described below apply to adults as well as children.
Normal and abnormal. Children are born with a considerable amount of farsightedness which is intended to automatically diminish with time and finely adjust the eye's refraction as they learn to focus on the world around them. It diminishes because the constant focusing effort for all distances causes the eye to lengthen. Excessive close work causes the eye to continue lengthening through the point of normal vision and into myopia. When your child's refraction has diminished to +0.5 diopters, it is time to take action, because the ideal refractive status is between +0.5 and 0 diopters. A minus refraction, indicating myopia, is abnormal. To determine this refractive status, you have the option of going to a vision specialist for an eye examination. But this costs money, and you will have to confront the doctor to insist that dilating eye drops are not used (See Toxic Dilating Drugs). Of course, if you suspect that your child has other vision problems than the possibility of becoming myopic, you should see the proper specialist. If your child's eyes do not work together properly, always consult an optometrist skilled in vision training. If you consult an ophthalmologist, you may be talked into unnecessary surgery as the only option. Numerous children have died while undergoing such surgery.
Vision testing. Let's assume you wish to avoid the doctors and do as much as you can yourself. To test visual acuity you can purchase the usual eye chart or make your own. To make one, cut letters of different sizes from a newspaper and paste them on a white background. Choose letters 3/8" high for the 20/20 row. This is really all you need, but if you want to add more rows, the letter sizes are: 5/16" for 20/15, 5/8" for 20/30, 3/4" for 20/40 and 15/16" for 20/50. Mount the chart against a vertical surface, put a good light next to it and place your child 20 feet away. If the child can read the 20/20 row with each eye separately, that is normal vision. To tell if the child still has a cushion of +0.5 diopters, just hold a lens of that power in front of each eye while covering the other eye. If the child can still read the 20/20 line, there is at least 0.5 D of farsightedness remaining. If the line is a little blurred, the child's refraction probably lies between +0.5 and 0 and preventive action is called for.
The child should not be sitting in the dark. Many vision specialists make this mistake. The pupil opens up, the periphery of the lens is used, and the result is that too much minus is prescribed.
Printable eye chart. Available on the Eye Chart page. Due to differences in monitor size and resolution, this test is not accurate when viewed on a computer. Also, there can be differences in printer resolution and setup. Therefore, the test includes a calibration bar that can be measured to determine that the letters are of the correct size.
Before testing, check that the length of the calibration line is 100 millimeters (3 15/16 inches). If it is different than 100 mm, multiply the length of the calibration line in millimeters by 1.2. This gives the distance that one should stand in inches from the test chart. Thus, if the calibration line is 100 mm, then the person taking the test should stand 100 mm X 1.2 = 120 inches, or 10 feet, from the chart. For variation, the chart can be turned upside-down, or sideways.
Test lenses. The obvious question is where to get a +0.5 D lens. You could use cheap off-the-rack reading glasses except for the fact that they usually start at +1 or +1.5 D. You could go to an optical shop and try to buy an uncut lens, but you would spend a lot of time explaining why you needed it and why you didn't have a prescription. The easiest solution is to go to the Order Form and order a Myopter lens of that power. This can merely be held in front of the eye when testing. However, since the lens is only 20 mm in diameter it will be easier to hold if you make a holder. Cut a 2" by 4" rectangle from a heavy corrugated cardboard box. Round off the corners. Lay the 20 mm lens 1/2 inch from one end and outline it with a pen. Then, using a sharp penknife, razor blade or curved scissors, cut a hole in the cardboard. Push the lens into the hole, add a little cement or tape if needed, and you have a convenient vison tester.
If you wish to monitor more closely how your child's vision is developing, you can go a step further and order several different lens powers, such as +0.5, +1.0, and +1.5. Then record the strongest lens the child can tolerate without seeing a blur at distance. Plot this on a chart periodically and you can extend the line ahead in time and determine when the child's vision is likely to pass the zero point into myopia.
There is no ideal preventive treatment that applies to everyone. One child may read a lot in school and nothing at home. Another child might do just the opposite. So here is a plan that you can use as a starting point and modify according to your own situation.
The Myopter. The Myopter with appropriate plus lenses is the first choice in preventing or reversing myopia. It should be used for all close work at home and even at school, if possible. It is available on our Products page. The book should be held far enough away that the print is just slightly blurred. This technique of reading at the far point FORCES the eyes to relax. If the child does not want to use it in school, then it should be used at home since that will help undo the stress that has built up during the hours spent in school. Then the next day's schoolwork can begin without building on a ciliary spasm from the day before. It should also eliminate any ciliary spasm that may be present and thus could reduce the myopia by a diopter or more. The Myopter eliminates the three factors associated with close work: accommodation, convergence and stereoscopic (3-D) effect. The eyes are thus fully relaxed as if looking into the distance.
The Myopter should be used as soon as the child has used up the infantile farsightedness and is moving into myopia. For such a child, this usually means +3 lenses. They should be used for all close work. Ideally, the book should be held far enough away so that the print is slightly blurred. Lower power plus lenses are suitable for those who are already myopic. It is also a good idea to use an undercorrection of 0.5 to 1.0 diopters for distance, in order to relax the eyes further by introducing a slight blur. Lens selection is explained on Closeup Lens Selection.
Reading glasses. Reading glasses are also very useful in preventing myopia. Lenses are selected in the same manner as for the Myopter. While reading glasses can be purchased off-the-rack in stores for a low price, those are suitable for adult-size heads. The distance between the lens centers conforms to the usual distance between the pupils of adult eyes. If such glasses are used by young children, who have a smaller interpupillary distance, the Prismatic Effect of the lenses causes increased convergence. In those people who have weak convergence, this can occasionally lead to temporary double vision and should be avoided. In their ignorance, eye doctors may refuse to prescribe a strong plus in a child's frame. That is why we offer kids' reading glasses on our Products page. These glasses have optical centers 60mm apart.
However, those store-bought glasses are useful in confirming what power to order for a child. Let your child try on various powers to determine which gives a slight blur at a comfortable reading distance. Then get that power in a smaller frame. There is no benefit in a lot of blur. A slight blur is enough to verify that the ciliary muscle is fully relaxed.
Any optician should be willing to measure your child's eyes and sell you a pair of reading glasses in a small frame, but they often refuse to do it. If they say you need a prescription, tell them that reading glasses can be bought in drugstores without a prescription. Or say that you are a scientist conducting an experiment! If they still give you a hard time, go somewhere else. And rather than pay inflated prices for a frame, you can buy a pair of kids' sunglasses in a store and then take them to an optician and only pay to have the plus lenses inserted. Another option is to buy glasses online without having to send in a prescription at sites like Zenni Optical, 39dollarglasses, eyebuydirect, globaleyeglasses, or discountglasses
The distance between the child's pupils should be measured when the eyes are converging on a book. Ideally, the centers of the eyeglass lenses should not be any farther apart than that distance. As the child grows, the pupils will become further apart than the optical centers. There is no harm in this because the prismatic effect of the plus lenses will then REDUCE the convergence required.
Another option is to use flip-up readers which are ideal for the child who needs distance glasses to see the board in school. When close work needs to be done, flipping the clip-on down gives a +3 diopter "add", eliminating the stress of close work. This is easier than having two pairs of glasses, one for far and one for near. It is available on our Products page.
Some people may have a problem with this technique. If they have weak convergence, they may find that without the assistance of accommodation they feel their eyes "pulling" or even see double. One way to ease the convergence in such cases is to decenter the plus lenses toward the nose, making use of the prismatic effect in a beneficial way. Those who need more assistance are perfect candidates for the Myopter, which eliminates all convergence as well as accommodation.
Why is the Myopter better than reading glasses? When we use our eyes, convergence and accommodation work together. Both increase when we look at something close. Thus, convergence stimulates accommodation in the brain and accommodation stimulates convergence. When we use reading glasses to eliminate accommodation, we are still exerting convergence and STIMULATING accommodation. This can prevent the complete relaxation of the ciliary muscle and make improvement more difficult. So, for maximum success, let your child use a Myopter at home and reading glasses in school where the Myopter might make the child uncomfortable because of its appearance. For more on this subject, read Myopter Research Paper.
Lens selection.To calculate the correct power of reading glass lenses, as well as Myopter lenses, see Close-up Lens Selection or use Email for assistance. However, the standard +3 add will not be enough for a child with short arms and who may be playing with an ipad for hours every day. Take the child to a drug store that sells reading glasses and try to determine how much plus she needs to get a slight blur at normal reading distance. You may have to put a couple of pairs on top of each other to do it. Suppose you determine that the child needs two +4 glasses. Since you cannot buy that power, you could order them in a kids frame from one of the several suppliers listed above that sell glasses without needing a prescription. Another way is to buy a pair of +1 and a +3 flip-up from www.myopia.org/products.htm.
Your role. Some people have stated that children won't accept the minor inconvenience of using the Myopter or reading glasses even at home. But, when children have been adequately informed of what is at stake, will they really choose instead the inconvenience of a lifelong dependence on glasses to see and the increased probability of eye disease? Point out a few people with thick glasses and ask your child if it isn't worth a little effort to avoid needing such glasses to see. Use the images below to illustrate the difference between normal vision and myopic vision:
These are the basic things you need to know to save your child's vision and save money at the same time. There is no need to pay inflated prices for stronger glasses every year or two.