Note: Otis Brown has been posting on the sci.med.vision newsgroup since December 30, 2002, on the subject of myopia control. He has presented the case that near work causes nearsightedness, and that the lenses traditionally prescribed to provide clear vision for the nearsighted, so called "corrective lenses" or "minus lenses", cause the condition to worsen by the same mechanism. He advocates a science-based preventive approach involving reading glasses, or "plus lenses", and has set up a web site on this subject, MyopiaFree.com. The following list of supposedly unanswered questions regarding Otis's position has been presented by sci.med.vision participant Neil Brooks. The answers to most of these questions may be found among the posts and referenced materials that Otis has presented on numerous occasions. We have decided to lay the answers out in a concise point-by-point format here. Those wishing further clarification from Otis on these or other myopia-related issues are invited to join his forum on Yahoo Groups, MyopiaFree2.
THE FOLLOWING QUESTIONS HAVE BEEN POSTED TO OTIS BROWN ON COUNTLESS (PROBABLY >100) OCCASIONS, YET HE HAS NEVER ANSWERED THEM HONESTLY, DIRECTLY, AND COMPLETELY.
Take a few minutes and read through them. Check the references cited within. Decide for yourself. If you think the questions are relevant, pressure Otis to answer them publicly.
QUESTIONS FOR OTIS:
1. There seems to be a great deal of evidence that primates have widely differing visual systems. How is it that you feel so secure in saying that "all primate eyes" behave similarly ... in ANY regard?
Primate eyes may differ with respect to color vision, but they are quite similar with with respect to the mechanism of accommodation, which is the aspect of visual system that is most relevant to the question of regulating refractive state relative to the visual environment.
2. In these monkey studies that you reference, isn't it true that the SAME STUDIES showed that, with even BRIEF periods away from the minus lens, the myopia was prevented?
No, myopia was not completely prevented. Its incidence and severity was merely lessened, as expected.
3. If there was no medical indication that these monkeys needed corrective lenses at all, can you be sure that appropriate CORRECTION of somebody's REFRACTIVE ERROR will have similar results? If so, how?
To say that a "refractive error" needs to be "corrected" is begging the question. The effect of adding a negative lens or increasing its strength in all cases is to change refractive state of the experimental animal's eye in a negative direction (towards myopia). It is reasonable to expect the same results if the original refractive state (before lens use) is negative. With very young animals, the "control" animal may recover from myopia, but the "experimental" (with minus lenses) animal will stay myopic. The effect of the minus lens is to shift the otherwise expected refraction in a negative direction.
4. You continually claim that a minus lens causes something that you call "stair-case myopia." Presuming that you mean that it does this in humans, do you have any valid clinical evidence for this claim?
In addition to the Oakley-Young study (see next question), please see the following articles by Antonio Medina: http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Search&db=pubmed&term=medina%20emmetropization:
Medina A. A model for emmetropization. The effect of corrective lenses. Acta Ophthalmol (Copenh). 1987 Oct;65(5):565-71.
Medina A. A model for emmetropization: predicting the progression of ametropia. Ophthalmologica. 1987;194(2-3):133-9.
Medina A, Fariza E. Emmetropization as a first-order feedback system. Vision Res. 1993 Jan;33(1):21-6.
5. You have repeatedly claimed that the Oakley-Young study is "proof" of this "stair-case myopia" phenomenon, but Oakley-Young only establishes that-in some people-myopia can get worse over time. It doesn't even CLAIM that a minus lens CAUSES this. Please explain your position.
The average rate of myopic progression for fully corrected myopes of the age studied by Oakley and Young is about -0.5D per year. Since the subjects of Oakley and Young's experiment "Bifocal Control of Myopia" (reproduced at http://myopia.org/bifocals.htm) had an average of zero myopia progression, and they did not receive full correction, this study is evidence that full correction causes myopia to increase.
6. Also-at least in part, based on the Oakley-Young study-you recommend that people use plus lenses to prevent myopia. Are you aware that the only people in the Oakley-Young study for whom plus lenses made ANY difference were those with diagnosed "near-point esophoria?" This is a convergence disorder. Do you have ANY EVIDENCE that the same result is likely with people who DO NOT HAVE this convergence disorder?
Nearpoint esophoria is a condition where one struggles to keep the eyes from crossing too much when focusing at the nearpoint (accommodating). Those with this condition have trouble reading through minus lenses, since minus lenses increase accommodation, it becomes even harder to keep the eyes aligned. Accordingly, nearpoint esophores are therefore more likely to actually use the "plus" segment of the bifocal for reading without being explicitly instructed to do so, since it reduces the need to accommodate when reading and makes it easier to keep the eyes aligned for such individuals. This is the only explanation of their success that makes sense. It is perfectly in line with the idea that plus lenses will reduce or limit myopia for anyone who uses them properly.
7. You claim to have known Donald Rehm, the founder of the International Myopia Prevention Association, for some decades. I presume that you are familiar with his FDA petition. In it, Mr. Rehm states:
" if we converge without accommodating the appropriate amount, or if we accommodate without converging the appropriate amount, problems can develop for this small percentage of children such as eye fatigue, double vision, or other types of fusion problems. That is, the two images can no longer be fused together without discomfort. Normal binocular vision is interfered with."
Is there a valid reason why you have not attempted to make people aware of these SERIOUS risks of unprescribed plus lenses?
For reference, here is a link to the petition:
http://myopia.org/fdapetition.pdf
The section quoted (found on pages 34-35) refers to difficulty "accepting" a large plus add, that is, difficulty using a strong plus lens. Don Rehm states in a footnote to the petition that the number of patients with this difficulty turned out to be less than 1% of the COMET study participants.They had trouble reading with the standard plus add prescribed for them, and so were given a different prescription, which did not give them problems.[ UPDATE Jun 28, 2008: Don Rehm got it backwards! It was those from the group that got the standard "single vision" minus lenses, not the group that got the "plus add" lenses who experienced binocular vision problems. The standard minus lens users who had these problems were switched to the "plus" (progressive add lens, or "PAL") group to eliminate these problems. There were no such problems reported in the group that got the plus adds! The COMET study paper states: "Two children changed lens assignments, both from SVLs to PALs, due to binocular vision problems." ]
As for "warning" people about this, please see chapter two of How To Avoid Nearsightedness by Otis Brown. The reader is indeed told that certain strengths of plus lens may turn out not to be able to be used comfortably. But the plus lens user is in crontrol. The section "How Do I Use the Positive Lens" reads:
If you habitually read closer, you will need a stronger lens. If you read at a greater distance you need a weaker lens. Some experimentation is in order here, and you may try several pairs of glasses before you find the right pair for yourself. In general, stronger is better, but you will want to be comfortable with the lens you choose.
If you have never used lenses before, you will notice a slight disorientation when you read close (with the lenses on) and then look in the distance over the tops of the lenses. This is a good indication that the lenses are having their desired effect. The reason for this is that the lenses have placed the near work at a distance while the convergence system believes the work is close by. This situation is normal and is part of the price one must pay to avoid nearsightedness.
So anyone who reads this book (which is linked to on the MyopiaFree.com home page) will have been "warned" about possible problems that might occur while using plus lenses that are too strong, as well as how to deal with them.
The "double vision" effect is also mentioned on Don Rehm's web site, linked to from plus-prevention promoting web site ChinaMyopia.org (a web site that Otis recommends): http://www.preventmyopia.org/faq.html:
Can a child just use reading glasses bought at a drug store?
No. A professional should be seen to obtain individualized advice.
Drug store reading glasses are intended for adult-size heads. The distance between the lens centers conforms to the usual distance between the pupils of the adult head. If such glasses are used by young children, who have a smaller interpupillary distance, the "prismatic effect" of the lenses causes increased convergence. This can cause problems such as double vision and should be avoided. The distance between the child's pupils should be measured when the eyes are converging on a book. The centers of the eyeglass lenses should not be any farther apart than that distance.
Whether or not this effect is a "serious" risk is a judgment that must be made by the person considering using plus lenses.
8. You continually cite Fred Deakins as a (questionable) success story. Do you think it is honest NOT to mention that Mr. Deakins is--in truth--myopic, that he is trying to sell a $40.00 product, and that his "testimonial" is used as an inducement to buy this product?
Fred Deakins is no longer in business so this point is moot. As for his "myopia", Fred started out at 20/70, but was able to achieve 20/15 vision through intensive use of the plus lens. When it was not a priority for him to pass the FAA exam, he stopped using the plus, and let his vision slip to 20/25.
9. Do you have any economic interest in the product sold by Mr. Deakins?
See above.
10. You claimed that you were not selling a book--until, that is, I provided links to websites where it WAS being sold for $24.95 (with your home address as the "send check to" address). You then claimed that the entire book was available for free on the internet--until, that its--I pointed out that only approximately four of 14+ chapters were on the internet. Would you please clarify whether or not you have ever received money for a copy of your book, "How to avoid nearsightedness: A scientific study of the normal eye's behavior?" If so, please state how many copies you have sold, and when the last copy was sold. If not, please state how long it has been since you received any money for this book.
This irrelevant ad hominem argument does not deserve a reply. All the information one needs to take control of one's vision using the plus lens is freely available at or linked from MyopiaFree.com, including the relevant chapters of the above-mentioned book, which is no longer being offered for sale.
11. Do you believe that it is dishonest NOT to mention that you have a commercial interest in inducing people to visit your website?
See above.
12. Presuming that you understand the difference between accommodative spasm (pseudomyopia) and axial-length myopia, would you please provide credible proof that either a) pseudomyopia CAUSES axial-length myopia, or that b) relieving pseudomyopia REDUCES axial-length myopia
Proof is in the eye of the beholder. But there is plenty of evidence that many eye doctors have found convincing:
- http://www.i-see.org/plus_therapy/
- http://www.preventmyopia.org/validation.html
- Ebenholtz 1983: "Accommodative hysteresis: a precursor for induced myopia?" [PubMed ID 6832921]
- Ebenholtz & Zander 1987: "Accommodative hysteresis: influence on closed loop measures of far point and near point." [PubMed ID 3610542]
- Ciuffreda & Wallis 1998: "Myopes show increased susceptibility to nearwork aftereffects." [PubMed ID 9727402]
13. You CONSTANTLY make reference to "Second Opinion" optometrists--presumably meaning those who share your views. Other than the now-infamous Steve Leung, are there ANY OTHER such "second opinion optometrists" in the ENTIRE WORLD? Does any of these people have any evidence to support the claims that you make? Would you please provide it?
Antonia Orfield, O. D, Boston, Massachusetts:
"Dr. Orfield offers unique and successful treatment programs for those who are nearsighted. Yes, she really has helped individuals get rid of their glasses (without surgery)." http://www.optometrists.org/Boston/index.html
Steve Gallop, O. D., Philadelphia, Pennsylvania:
"Dr. Gallop specializes in myopia reduction. He has helped countless people prevent, reduce or eliminate the need to wear lenses to see clearly in the distance. Nearsightedness (myopia) frequently gets worse due to wearing the lenses prescribed by most doctors to 'correct' the problem." http://gallopintovision.com/
Merrill Bowan, O.D., Pittsburgh, Pennsylvania:
"Preventive lenses - 'Plus 50' or 'Plus 75' reading lenses are powerful tools against myopia for most students, beginning as early as second grade for most, though some students are showing signs of this developmental nearsightedness by the middle of first grade." http://www.nb.net/~sparrow/myopianear.html
For more such optometrists, see http://www.i-see.org/eyedocs.html
14. Mr. Steve Leung is also trying to sell a book. Do you have any economic interest in the book sold by Steve Leung? Do you think it is honest NOT to mention that Mr. Leung is--in truth--myopic, that he is trying to sell a book, and that the "testimonials" on his website, and your repeated referrals TO his website are used as inducements to sell both your and his book?
Steve Leung's book is available for free download in Chinese on his web site, along with much other completely free material on myopia prevention in English. http://www.chinamyopia.org/mainenglish.htm
15. Do you feel that it is HONEST NOT TO admit that--even though your niece, Joy, NEVER WORE MINUS LENSES, and DID USE PLUS LENSES, she is, at this time, a myope with a restricted driver's license? [http://www.chinamyopia.org/otis%20&joy.htm]
Although her distance vision is not 20/20, Joy successfully avoided the need to wear glasses. The "restriction" for driving mentioned in the above article is that she have a side mirror, not that she needs to wear glasses. Plus lenses helped her to the extent that she used them. Please read the above-linked page and judge for yourself.
16. I have posted, many times, links to the actual summaries of the myopia progression studies that you lie about [http://darwin.nap.edu/books/0309040817/html/62.html.] Why do you tell people that they WILL SHIFT MYOPIC BY 1.3 DIOPTERS during the four years of college when the studies DO NOT SAY THAT AT ALL? Please explain your position and provide citations to the appropriate studies.
The studies summarized on pages 26 and following of the National Research Council's 1989 book Myopia: Prevalence and Progression show that the average change in refraction of a myope after entering a military academy is about one quarter to one third negative diopters per year. This is a statistical finding and should be understood in that context. Those who do not wear corrective glasses for myopia, and who do not study too hard may avoid this shift. However, only 1% of those entering with 20/25 unaided distance vision will see at 20/20 upon graduation.* If you have myopic tendencies, the chances of recovering from myopia in the school environment, if you do nothing, or especially if you wear corrective lenses, are slim to none.
* Reynolds Hayden, "Development and Prevention of Myopia at the United States Naval Academy", Archives of Ophthalmology 25(4):539-541
17. You enjoy citing the Francis Young 1969 Eskimo study, claiming
that it is "proof that near work causes myopia." Are you aware of the
contemporary theory that states that, in fact, myopia in the Inuit
population was a result of the introduction of a "Western" diet high
in simple carbohydrates (junk food)?
http://www.second-opinions.co.uk/myopia.html
http://www.newscientist.com/article.ns?id=dn2120
This theory does not contradict the idea that too much near work causes myopia. The studies referenced in the above articles do not show that a high-carb diet is sufficient to cause myopia. The islanders who kept their low-carb diet while going to school still had a relatively "open" environment. According to Optometrist Theodore Grosvenor, who participated in one of the surveys, "The school day in Vanuatu is short and children spend their after-school hours working in the family garden, attending to the chickens and pigs and fishing in the local streams. The only children who remain in school after age 12 or 13 are those whose parents plan for them to further their education in Australia or New Zealand" http://www.optometrists.asn.au/ceo/backissues/vol86/no5/2312
18. You enjoy using the term "closed-loop feedback system" to describe your concept of the "dynamic eye," yet (see question #3) the following is a much BETTER representation of a closed-loop feedback system:
Think of your home's oven as an analogy.
You set the thermostat for 350 degrees (F).
If the oven is already at 275F, then the thermostat will signal an INcrease in temperature.
If the oven is already at 425F, then the thermostat will signal a DEcrease in temperature.
IF, however, the oven is already at 350F -- the desired temperature -- then the thermostat will not signal any change.
Please explain why your position is at variance with this analogy.
The "desired" refraction of the eye is determined by its visual environent. In a "caged" environment, this refraction will be negative, say -0.75 D. When a -0.75 D "correction" is applied, the eye's "detected" refraction will become 0.0 D, and will adapt by adapting towards a refraction of -1.50 D for a net refraction of the "desired" -0.75 D.
19. You seem to stop by sci.med.vision for the sole purpose of "roiling the waters--" adding posts designed only to harrass and annoy optometrists who, universally, do not agree with you.
You then excerpt--often improperly and with incorrect attributions-- these conversations on other sites, adding your little 'comments' WITHOUT the doctor having any ability to challenge what you say.
Do you think this is intellectually honest?
If you are interested in debate, exchange, argument, or discussion, wouldn't it be better to actually ANSWER questions directly?
This ad hominem attack does not deserve a response.
20. Presuming that your theories are based, at least in large part, on the emmetropization process, at what age does this stop in humans? In other words: you are recommending a particular therapy to halt myopia progression that--based on your arguments--should be equally effective at REVERSING it. If so, then why are all of its advocates (and most of its known 'test subjects') myopic?
This seems to be a bit of a paradox, no?
Researcher Josh Wallman states: http://www.neuron.org/content/article/abstract?uid=PIIS0896627304004933 "Although emmetropization is generally thought of as occurring during early development, homeostatic growth mechanisms need to be at least as precise during maturity if size is to be tightly maintained.... In humans as well, there is evidence of changes in ocular dimensions in young adults associated with the progression of myopia, perhaps related to visual tasks (McBrien and Adams, 1997). Thus, the young adult eye is still subject to visually guided growth."
We can only state with confidence that a small amount of myopia -- up to the 20/70 level -- can be completely eliminated, and even then, it must be caught early. In general, the longer the condition has persisted, and the further it has progressed, the harder it will be to reverse. Unfortunately, many of the "second opinion" doctors discovered the preventive principle too late to help themselves. Fortunately, they are helping others at the threshold, including their own children.