Why7 Subject: The Snellen Eye Charts Note: We are in desperate need of a prevention-minded optometrist like Steve Leung to help us with vision-clearing. See: www.chinamyopia.org There is a great deal that you can do to help yourself -- until you find a supportive prevention-minded optometrist. Checking your visual-acuity yourself is that first step. +++++++++++++++++++++++++++++++++++++++++++++++++++ The Snellens are in on the myopiafree page: It is a good idea to do a general verification check on these Snellens. The standard chart distance is 20 feet. Just measure the 20/60 letter size. It must be one inch in size. If that is correct, then the rest of the Snellen should be accurate for your purposes. In general, if you read 1/2 the letters correctly, you pass that given line. In most states the requirement is for 20/60 to 20/40 vision. These are the lines you MUST PASS to receive a valid DMV license to drive a car with naked-eye vision. On the path to vision clearing you will "clear" these lines. Obviously the goal is to get your visual-acuity above these standards. You should verify your vision before you go take the DMV test. It is often said that "vision improvment" is because the person memorized the Snellen. This is the reason you should use the IVAC (Random) Snellen, for a very accurate confirmation of your visual acuity. That is why the IVAC-Monitor Snellen is best. ++++++++++++++++++++++++++ WHY PREVENTION IS NOT OFFERED. (Except by Steve Leung OD) We might ask why a myopia prevention discussion is not offered by optometrists. Here are some of the reasons for this reluctance to discuss the possibility of prevention with a person whose vision is 20/50 to 20/70. I acknowledge that it takes a strong person to implement prevention at the 20/50 level -- when we judge that the effort must start, so that the effort can become effective. The one thing that bothered me as I was digging into the question of nearsightedness was that I was challenging established authority. This type of a questioning attitude is necessary in science -- and we should understand some of the objections that exist concerning effective prevention with a plus lens. OPTOMETRISTS HAVE PRACTICALLY NO CHOICE (IN MOST CASES) BUT TO USE THE MINUS LENS. As I became friends with ophthalmologist and optometrists I realized that they did not "love" the minus lens either -- but they had no choice at all but to use it if vision was more negative than 20/70. Some optometrists have called the minus lens "poison glasses for children". This fact should provide you with a sense of their judgment (and frustration) about the secondary effect that the minus lens on the eye. In fact I greatly respect the few optometrists who challenge the existing theory (Donders-Helmholtz). This concept insists that the natural eye does not change its status in a negative direction from either a forced confined environment or the forced wearing of a minus lens. Many optometrists have understood these basic facts. For this reason they choose to NOT PRESCRIBE the minus lens at all. This is possible, but ONLY if the child's distant vision meets the DMV standard of 20/40 or better, While the intention is understood, the decision to avoid the use of a minus lens does not work in the long run. In other words, doing nothing for "prevention" at that point does not work. This is because the child will go back to his bad reading (at 4 inches) habit -- and will simply gets deeper into it. See the analysis of the effect of a primate eye in Chapter 6 of my book. Also look at the -12 diopter picture if you do not believe me. Eventually, with the habit of reading at 4 inches (optically, -10 diopters) the eye becomes even more negative. When it is at -0.75 diopters (20/60) the optometrist has no choice at all but to apply the minus lens. A great deal of responsibility must rest with "us" to prevent this bad habit in children. The optometrist should be more forceful in explaining this type of responsibility that we must assume. There is need for a strong "second opinion" discussion concerning the use of the plus lens at this point, and the long-term consequences of NOT using the plus properly. This is indeed a now-or-never decision. If the person can master the "preventive" skills, then the child, parents and optometrist can be effective in restoring the child's distant vision to normal at that point. But the effort must not stop at that point, and must be continued AFTER the child reaches 20/20. In fact the strength of the plus used for reading should be increased by +1/2 diopter, when the child's vision changes by +1/2 diopter. Since no optometrist or ophthalmologist can stop your child from reading at 4 inches (optically -10 diopters) it follows that the optometrist can only react to the eventual effect this bad habit has on the child's focal status. When you talk honestly with some ophthalmologists you find that they also realize that this reading at 4 inches produces the resultant (negative change of focus) of their eyes into nearsightedness. This is a major problem and the child and parents must understand the need to stop this type of reading. Please click on "-12 D" to see a child doing this. The "classical" theory insists that reading at this distance has NO EFFECT ON THE REFRACTIVE STATUS OF THE EYE. The development of nearsightedness can not be stopped until this nose-on-the-book habit is stopped completely. But the parents and their child often fail to recognize this issue and problem at the time. For this reason the optometrists states, " ...but the public will not accept advocacy for prevention with a plus lens". In most cases they are right on that point. They state that they have no choice but to do what the public expects -- which is to make your child's vision instantly sharp with a strong minus lens. Unless you are "wise" about this issue at the threshold, you will not tolerate the use of a plus lens for your child. Until we learn to break ourselves of this cycle at the start we can not resolve this issue of personal responsibility and control for preventing nearsightedness. This is necessary a "shared" responsibility with you and your child taking responsibility to do what is necessary. Tragically, both the doctor and patient seem to always be marching downward by our use of the minus lens -- because it is so easy and quick, and requires no discussion, review or choice. It will take strong personal resolve to prevent this situation from the start. But let anyone suggest that "all natural eye move minus when a minus lens is placed on them", (which is a matter of direct experimental, scientific and factual truth) and a great many people (including optometrists) get upset. At some point you must begin to share "authority" -- by putting on your "scientific hat" and acting more competently about advocacy for prevention with a plus lens. To ignore the warning about this issue is to accept the ultimate long-term consequences. This intellectual and scientific process fact review should lead to a restating of the problem. This work will produce a better-organized effort at prevention. In this struggle no one should suggest that I disrespect optometrists. In fact they have argued FOR PREVENTION as the "second opinion." I strongly support that advocacy, and we need to understand the use of the plus on that basis. PROFESSIONAL ADVOCACY FOR PREVENTION In fact, the recommendations made on this site have been amplified and repeated by the professionals. Dr. Theodore Grosvenor of the University of Houston College of Optometry insists that persistent close work causes the eye to "change" in a negative direction. He further states that, "Once the eye has started to stretch, it may be too late to keep it from stretching". This should be a warning to us about the need to start using the plus -- before the minus lens is applied. Further, as the minority opinion, we agree that, "The ultimate study would be to put reading glasses on first-graders before anyone has developed myopia" as Theodore states. What prevents us from taking this major step for the welfare of our own children?