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Other children making more than one attendance at the clinic during the year are
cases of myopia, those for treatment of external eye diseases} also those with broken
glasses.
DEFECTIVE COLOUR VISION. The Ishihara Test for the detection of this defect has
only been carried out in the case of children attending grammar and other higher schools,
for boys who have entered for Sea Training Scholarships, and for those children who propose
entering services where correct cojour discrimination is necessary. Defective colour vision
is of fairly frequent occurrence in males - about one in every 20 being affected, but is
much less common among girls. It Is such a severe handicap in certain occupations that it
is clearly in the child's interests that it should be discovered before his career is
decided. At the examinations held at the Grammar and Technical Schools and in connection
with the examination of boys for Sea Scholarships, the following results were obtainedj-
Number Number Percentage
Examined Defective Defective
Boys 529 31 5.86
Girls 1+56 .1 0.22
VISUAL SURVEY. Towards the end of the year, the results were received of the survey
of visual defects conducted in West Ham by Professor Sorsby and his colleagues under the
auspices of the Royal College of Surgeons. This took place in 1948-49 with the approval
and co-operation of the Education Committee and involved the examination of some 65O
children in their last year at school, whose parents had given their consent.
The evaluation of the findings have required a very extensive statistical analysis
which would occupy too much space to be included in this report. In brief, many children
were found to have defects of vision which would not be brought to light by the ordinary
routine tests for visual acuity. Abnormalities of varying degrees were discovered in such
functions as convergence, accommodation, binocular vision, colour vision, dark adaptation
and muscle-balance.
For some of these functions, it was expected that the efficiency would vary from
child to child over a very wide range and so it has turned out; but standards had not been
clearly established which would separate the "normal" from the "defective" vision. As in
so many human measurements - stature, strength, intelligence, etc., - there is no one
"perfect" value, but rather a range of values within which the majority of able individuals
are embraced. This range is regarded as the "normal" and it is not always easy to decide
Just where its limits should be set. The survey has provided reliable data for assessing
the normal values of many of these functions, and in the case of two of them convergence
and accommodation - it became clear as the analysis proceeded that the standards of normality
provisionally adopted would have to be somewhat relaxed.
Thus the survey has helped to determine the normal range of several visual functions
which are not usually tested, to establish the fact that many children are defective in one
or more of these respects, and to estimate the proportions of children so affected. It was
found that the proportion of children with defects ranged from about 1-2 per cent, up to
about 8 per cent, according to the nature of the visual function tested.
So far this research has been purely fact-finding. Now a number of practical
questions arise which require an answer. Are these visual defects likely to prove a
handicap, either in employment or in any other walk of life ? Are they likely to
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