10-30-2006, 08:03 PM
Bate2040.txt
Subject: What is the origin of the DMV Visual Acuity
Standard?
The visual acuity test (20/20) means reading 3/8 inch letters
at 20 feet. The DMV standard is for 20/40, or 3/4 inch letters at
20 feet. For some states, the standard is 20/70 (Florida), 20/60
(Georgia) and 20/50 (Texas). In working to clear your vision, it
is necessary to be close to passing these "standards". Here is
the reason why the standard was change.
The term "normal 20/20" in reality meant that the retina had
the capability of 20/20 -- with a proper strength minus lens.
The idea that a large number of people have naked-eye 20/20
is simply in error.
The various "qualifying" agencies recognized this truth, and
made the decision to use a REASONABLE visual-acuity standard as
stated below.
For anyone working to "clear" his vision, I think he should
set the major goal of personally passing the DMV standard to be
legal.
Here is the background of these standards.
========================================
Statements by W. Bates about the change from 20/20 to 20/40
-- 20/100 for visual acuity.
Up to 1908 the United States required normal vision in
recruits for its military service. In that year Bannister and
Shaw made some experiments from which they concluded that a
perfectly sharp image of the target was not necessary for good
shooting, and that, therefore, a visual acuity of 20/40 (the
equivalent in feet of 6/12 in meters), or even 20/70, in the
aiming eye only, was sufficient to make an efficient soldier.
This conclusion was not accepted without protest, but normal
vision had become so rare that it probably seemed to those in
authority that there was no use insisting upon it; and the visual
standard for admission to the Army was accordingly lowered to
20/40 for the better eye and 20/100 for the poorer, while it was
further provided that a recruit might be accepted when unable with
the better eye to read all the letters on the 20/40 line, provided
he could read some of the letters on the 20/30 line. (1)
+++++++++++++++
1. Harvard Manual of Military Hygiene for the Military Services
of the United States, published under the authority and with
the approval of the Surgeon General, U. S. Army third
revised edition, 1917, p. 195.
+++++++++++++
In the first enrollment of troops for the European war(WWI
OSB) it is a matter of common knowledge that these very low
standards were found to be too high and were interpreted with
great liberality.
Later they were lowered so that men might be "unconditionally
accepted for general military service" with a vision of 20/100 in
each eye without glasses, provided that the sight of one eye could
be brought up to 20/40 with glasses, while for limited service
20/200 in each eye was sufficient, provided the vision of one eye
might be brought up to 20/40 with glasses. (2)
++++++++++
2. Standards of Physical Examination for the Use of Local Boards,
District Boards, and Medical Advisory Boards under the
Selective Service Regulations, issued through the office of
the Provost Marshal General, 1918.
+++++++++++
Yet 21.68 per cent of all rejections in the first draft, 13
per cent more than for any other single cause, were for eye
defects, (1) while under the revised standards these defects still
constituted one of three leading causes of rejection. They were
responsible for 10.65 per cent of the rejections, while defects of
the bones and joints and of the heart and blood vessels ran,
respectively, about two and two and a half per cent higher.
For more than a hundred years the medical profession has been
seeking for some method of checking the ravages of civilization
upon the human eye. The Germans, to whom the matter was one of
vital military importance, have spent millions of dollars in
carrying out the suggestions of experts, but without avail; and it
is now admitted by most students of the subject that the methods
which were once confidently advocated as reliable safeguards for
the eyesight of our children -- have accomplished little or
nothing. Some take a more cheerful view of the matter, but their
conclusions are hardly borne out by the army standards just
quoted.
By Dr. W. H. Bates
Subject: What is the origin of the DMV Visual Acuity
Standard?
The visual acuity test (20/20) means reading 3/8 inch letters
at 20 feet. The DMV standard is for 20/40, or 3/4 inch letters at
20 feet. For some states, the standard is 20/70 (Florida), 20/60
(Georgia) and 20/50 (Texas). In working to clear your vision, it
is necessary to be close to passing these "standards". Here is
the reason why the standard was change.
The term "normal 20/20" in reality meant that the retina had
the capability of 20/20 -- with a proper strength minus lens.
The idea that a large number of people have naked-eye 20/20
is simply in error.
The various "qualifying" agencies recognized this truth, and
made the decision to use a REASONABLE visual-acuity standard as
stated below.
For anyone working to "clear" his vision, I think he should
set the major goal of personally passing the DMV standard to be
legal.
Here is the background of these standards.
========================================
Statements by W. Bates about the change from 20/20 to 20/40
-- 20/100 for visual acuity.
Up to 1908 the United States required normal vision in
recruits for its military service. In that year Bannister and
Shaw made some experiments from which they concluded that a
perfectly sharp image of the target was not necessary for good
shooting, and that, therefore, a visual acuity of 20/40 (the
equivalent in feet of 6/12 in meters), or even 20/70, in the
aiming eye only, was sufficient to make an efficient soldier.
This conclusion was not accepted without protest, but normal
vision had become so rare that it probably seemed to those in
authority that there was no use insisting upon it; and the visual
standard for admission to the Army was accordingly lowered to
20/40 for the better eye and 20/100 for the poorer, while it was
further provided that a recruit might be accepted when unable with
the better eye to read all the letters on the 20/40 line, provided
he could read some of the letters on the 20/30 line. (1)
+++++++++++++++
1. Harvard Manual of Military Hygiene for the Military Services
of the United States, published under the authority and with
the approval of the Surgeon General, U. S. Army third
revised edition, 1917, p. 195.
+++++++++++++
In the first enrollment of troops for the European war(WWI
OSB) it is a matter of common knowledge that these very low
standards were found to be too high and were interpreted with
great liberality.
Later they were lowered so that men might be "unconditionally
accepted for general military service" with a vision of 20/100 in
each eye without glasses, provided that the sight of one eye could
be brought up to 20/40 with glasses, while for limited service
20/200 in each eye was sufficient, provided the vision of one eye
might be brought up to 20/40 with glasses. (2)
++++++++++
2. Standards of Physical Examination for the Use of Local Boards,
District Boards, and Medical Advisory Boards under the
Selective Service Regulations, issued through the office of
the Provost Marshal General, 1918.
+++++++++++
Yet 21.68 per cent of all rejections in the first draft, 13
per cent more than for any other single cause, were for eye
defects, (1) while under the revised standards these defects still
constituted one of three leading causes of rejection. They were
responsible for 10.65 per cent of the rejections, while defects of
the bones and joints and of the heart and blood vessels ran,
respectively, about two and two and a half per cent higher.
For more than a hundred years the medical profession has been
seeking for some method of checking the ravages of civilization
upon the human eye. The Germans, to whom the matter was one of
vital military importance, have spent millions of dollars in
carrying out the suggestions of experts, but without avail; and it
is now admitted by most students of the subject that the methods
which were once confidently advocated as reliable safeguards for
the eyesight of our children -- have accomplished little or
nothing. Some take a more cheerful view of the matter, but their
conclusions are hardly borne out by the army standards just
quoted.
By Dr. W. H. Bates
