As well of the opinion that while the minus does indeed
make vision instantly SHARP, it has a serious and
adverse "secondary" effect.

Subject:  The Effects of "Corrective" Lenses:  Insight and
     Comment From Eye Doctors

    No clinical or statistical studies have ever demonstrated the
long-term safety of a (minus) "corrective" lens.

    In fact, a certain percentage of doctors believe that -- as the
second-opinion -- "corrective" lenses (also known as
"compensatory" negative lenses) usually create dependency and
make the eyes move more rapidly in a negative refractive direction.

    These concerns have been voiced in the professional
literature by concerned doctors who support the concept
the "second opinion" to do work for the prevention of nearsightedness
with a plus lens.

    Here are sample excerpts from the professional literature voicing
concerns about the safety of "corrective" lenses:

    "The use of compensatory lenses to treat or neutralize the
symptoms does not correct the problem.    The current education and
training of eye care practitioners discourages preventive and
remedial treatment." R.L.  Gottlieb, Journal of Optometry and
Visual Development, 13(1):3-27, 1982.

    "The emphasis on compensatory lenses has posed a problem for
many years in our examinations.  These lenses do not correct
anything and may not serve the patient in his best interests over
a period of time." CJ.  Forkiortis, OEP Curriculum, 53:1, 1980

    "There are frequently ignored patterns of addiction to minus
lenses.  The typical prescription tends to overpower and fatigue
the visual system and what is often a transitory condition becomes
a lifelong situation which is likely to deteriorate with time." S.
Gallop, Journal of Behavioral Optometry, 5(5):115-120, 1994

    "Single-vision minus lenses for full-time use produce
accommodative insufficiency associated with additional symptoms
until the patient gets used to the lens.  This is usually
accompanied by a further increase in myopia and the cycle begins
anew." M.H.  Birnbaum, Review of Optometry, 110(21):  23-29, 1973.

    "Minus lenses are the most common approach, yet the least
likely to prevent further myopic progression.  Unfortunately, they
increase the near-point stress that is associated with
progression." B.  May, OEP Publications, A- 112, 1984.

    For more information on this "sea change" in attitude to
work towards effective prevention with the plus please read:

http://www.eyelasers.co.uk/11/plus-lens-myopia.html

++++++++++

On Jul 22, 10:42 pm, "otisbr...@pa.net" <otisbr...@pa.net> wrote:

Perhaps you can explain what your point is here.

If you are referring to the fact that many kids choose to sit up close
to their reading material then what I would say is "SO WHAT".  That
has never been shown to have any impact on myopia development.  In
fact, hyperopic kids are most commonly the ones who sit closest to
their reading material.

And of course, Dr. Young endorces Steve Leung's
second-opinion, and his preventive work
with the plus:

http://www.geocities.com/otisbrown17268/FAYoung.html

The majority-opinion does not agee, but that
is just normal.

On Jul 22, 10:42 pm, "otisbr...@pa.net" <otisbr...@pa.net> wrote:

On Jul 22, 10:56 pm, "otisbr...@pa.net" <otisbr...@pa.net> wrote:

Otis,
do you think its normal for a person to carry on a conversation with
themselves on an internet newsgroup?

so here you go posting decades-old articles and opinions written by a
physicist who knows nothing about vision.

well here is a few references for you written by real experts in the
field who actually do experiments and analyze their data compared to
control groups:

Ong E, Grice K, Held R, Thorn F, Gwiazda J.
Optom Vis Sci. 1999 Jun;76(6):363-9.
Effects of spectacle intervention on the progression of myopia in
children.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1
0416930&dopt=Abstract

(snip)

Based on their wearing patterns, subjects were divided into four
categories: (1) full-time wearers; (2) myopes who switched from
distance to full-time wear; (3) distance wearers; and (4)
nonwearers. Exponential functions were fit to the individual
refraction data. The age of onset of myopia, the mean myopia at
onset of spectacle wear, and the refractive shift over a period of
at least 3 years were derived from these fits. Results show that the
3-year refractive shifts are not significantly different among the
four groups.

=============
Arch Ophthalmol. 1999 May;117(5):638-42.
Does overcorrecting minus lens therapy for intermittent exotropia
cause myopia?

Kushner BJ. Pediatric Eye and Adult Strabismus Clinic, Department of
Ophthalmology and Visual Sciences, University of Wisconsin, Madison,
USA.
RESULTS: At the time of initial examination, the mean (+/-SD)
refractive error was 0.00 +/- 1.40 diopters (D) in the control
group, 0.00 +/- 1.50 D in the study group, and -0.10 +/- 1.50 D in
the 5-year study group, all of which were essentially identical.
Five years after initial examination, the mean change in refractive
error was -1.40 +/- 2.80 D in the control group, -1.52 +/- 1.80 D in
the 6-month treatment group, and -1.54 +/- 1.80 D in the 5-year
treatment group. These differences in the change in refractive error
(myopic shift) were not statistically significant (t test), and the
differences are clinically unimportant. CONCLUSION: Overcorrecting
minus lens therapy for intermittent exotropia does not appear to
cause myopia.

===================

Ophthalmology 2002 Mar;109(3):415-21
Interventions to retard myopia progression in children: an evidence-
based
update.
Saw SM, Shih-Yen EC, Koh A, Tan D.

.. snip ..

CONCLUSIONS: The latest evidence from randomized clinical trials does
not
provide sufficient information to support interventions to prevent
the
progression of myopia.

================

Am J Optom Physiol Opt. 1982 Oct;59(10):828-41. PMID: 7148977
Attempts to reduce the rate of increase of myopia in young people--a
critical literature review.

Goss DA.

Results with, and opinions on, various experimental treatments for
increasing myopia in young people are presented and discussed. None of
the
many different therapies has been shown to be consistently effective
in
reducing the rate of increase of myopia. The difficulties encountered
in
conducting clinical research of this nature are discussed.

=================

Am J Optom Physiol Opt. 1984 Feb;61(2):112-7.

Plus lens, prism, and bifocal effects on myopia progression in
military students, Part II.

Shotwell AJ.

   Military academies routinely lose a percentage of their pilot-
qualified students to myopia during the 4-year academic program. This
study investigated the progression of myopia during such a program and
evaluated the usefulness of reading glasses to prevent myopia
progression and subsequent acuity loss. A group of students at the
United States Naval Academy comprised three randomly divided groups: a
placebo group (no. 1 pink tint), a plus with prism group (+1.25 D with
2 delta base-in each eye), and a bifocal group (+1.50 D near
addition). All the lens powers were relative to the experimental
subject's distance refraction and were for use full-time when reading.
The pre- and post-test refractive errors at distance were determined
using 1% tropicamide HCl. At the end of 4 years, the tropicamide
refraction showed approximately -0.25 D of myopic shift in all groups.
There were no significant differences between the myopic shifts in the
controls and experimental groups.

==============

The Hong Kong Progressive Lens Myopia Control Study: Study Design and
Main Findings
Marion Hastings Edwards, Roger Wing-hong Li, Carly Siu-yin Lam, John
Kwok-fai Lew and Bibianna Sin-ying Yu; Investigative Ophthalmology and
Visual Science. 2002;43:2852-2858.

University, Kowloon, Hong Kong.

Abstract:
PURPOSE. To determine whether the use of progressive addition
spectacle lenses reduced the progression of myopia, over a 2-year
period, in Hong Kong children between the ages of 7 and 10.5 years.

METHODS. A clinical trial was carried out to compare the progression
in myopia in a treatment group of 138 (121 retained) subjects wearing
progressive lenses (PAL; add +1.50 D) and in a control group of 160
(133 retained) subjects wearing single vision lenses (SV). The
research design was masked with random allocation to groups. Primary
measurements outcomes were spherical equivalent refractive error and
axial length (both measured using a cycloplegic agent).

RESULTS. There were no statistically significant differences between
the PAL and the SV groups for of any of the baseline outcome measures.
After 2 years there had been statistically significant increases in
myopia and axial length in both groups; however, there was no
difference in the increases that occurred between the two groups.

CONCLUSIONS. The research design used resulted in matched treatment
and control groups. There was no evidence that progression of myopia
was retarded by wearing progressive addition lenses, either in terms
of refractive error or axial length.

==============

Chung K, Mohidin N, O'Leary DJ. Undercorrection of myopia enhances
rather than inhibits    myopia progression. Vision Res. 2002, 42:
2555-9.

The Chung study is a small (n=94), 2 year randomized and masked
prospective study comparing the effects of full-time undercorrection
(UC, by approx 0.75 D) with full-time fully correction (FC) in young
myopes (mean: -2.86 D). The study group comprised approximately 1.4
time the numbers of girls as boys with Chinese and Malay ethnic groups
being approximately equally represented. Over the 2 years of the
study, the FC group showed a progression of -0.77 D compared to the UC
group that exhibited a progression of -1.00 D. Rates of eye growth
also differed between the two groups, as expected, being slower for
the FC group.
This study suggests that leaving myopes partially uncorrected (i.e.
with a net plus prescription) may in fact promote myopia development
rather than reduce it.

======