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Use of a + 1 Sphere before the Reading Eye in the Routine Vision Testing of
Children in School.
Last year I gave a detailed report of this procedure during the year 1932, having reported
in 1931 on results obtained by two months' use of this test in that year.
It will be remembered that the Committee of Inquiry into Problems connected with defective
Vision in School Children issued a Report in 1931 in which the above procedure was advocated
as a means of picking out early myopes who would otherwise be overlooked by the ordinary
Snellen Long Distance Test.
Roth my reports were concerned solely with those children who, without spectacles, read
either 6/6 or 6/9 with the Snellen Long Distance Test, and who had no signs of eye strain.
The results obtained showed that a large number of children had their vision adversely
affected by placing a +1 sphere before the reading eye (90% in 1932), but refraction alone would
have showed whether such children were emmetropic or suffering from slight hypermetropic
astigmatism or slight myopia. Refraction of such a large number of children is impossible in
routine work and therefore this new procedure offered no help in the detection of early myopes.
Under 1% of the 1932 children (25 in number) had their vision reduced by 5 or 6 Snellen
lines and 20 of these were refracted, showing slight myopia and slight hypermetropia combined in
many cases with an astigmatism of 0.25 diopter.
In three cases only were spectacles prescribed, two of these showed signs of eye strain, and
the third had a deterioration of vision, not apparent when the child was tested eight months
previously.
It was decided therefore to follow up the remaining 17 cases and to continue using the +1
sphere in the routine vision testing during 1933 and to mark for observation any cases whose
vision was diminished by 5 or more Snellen lines.
Results of following up 17 Children whose Vision at the Routine Medical Inspection in
1932 was diminished by 5 or more Snellen Lines when reading through a + 1 Sphere.
Five children had left before another Inspection or Re-inspection took place at their school.
Eleven children have been re-examined and in all cases their vision remained satisfactory
and there were no symptons of strain.
One boy was absent from school and has not been seen.
The three children for whom spectacles were prescribed were placed on the Refraction
Clinic Register and will be called again to the Clinic in twelve months.
In 1933 there were only two children whose vision was diminished by 5 Snellen Lines when
a +1 sphere was placed before the reading eye Both were girls aged respectively 12 and 13.
The latter, aged 13, is at the Central School where children are examined annually and is one of
the seventeen children who were followed up from 1932. Both girls have been re-examined and
their vision remained satisfactory.
In the light of the results obtained since November, 1931, by the use of a +1 sphere before
the reading eye in the routine testing of vision of school children, it would appear that this procedure
fails to detect early myopia.
It entails a considerable addition to the work, and since its results are inconclusive it has
been decided to discontinue its use.
Refraction of all children seen at the Routine Medical Inspection is the only sure way of
detecting early myopes, but such a large increase of work is impossible with the present staff of
the School Medical Service, neither is universal refraction desirable on account of the unnecessary
interruption of school work to numbers of children who would be found to need no spectacles.
It is also a debatable point as to whether small errors, even though myopic, should be
corrected in children with good vision and no symptons of strain.
I feel strongly that spectacles should not be prescribed in such cases although it would be
advisable to follow up such children.
The Snellen Long Distance Test combined with an enquiry into any symptoms of eye strain
is a useful and sufficiently reliable means of weeding out children who need further examination
by refraction.
Under the present system, however, children are only tested at three or four year intervals,
during which time defects may manifest themselves and often escape detection by parent or
teacher.
I am of opinion that the most useful reform in the routine vision testing of school children
would be to increase the frequency of these tests.
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