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112
Annual Report of the London County Council, 1913
Amb.=Amblyopic.
RI.S.=Right internal strabismus
L.I.S.—Left internal strabismus.
Dr. Macdonald's results are based upon rather small numbers, but they tend to show that it is
possible to demonstrate by special methods of investigation a very much higher proportion of
normal visual acuity in infant children than is obtained in the ordinary routine inspections in the case
of even the oldest age group, i.e., 84 per cent, girls and 86 per cent, boys in entrants, as against 43.8
per cent, girls and 51.18 per cent, boys in the older age group, and further thab the cases of serious
visual defect are much rarer amongst infants than amongst older scholars. It is probable, however,
that if all the children had been tested under a mydriatic it would have been found that a much
larger proportion of the infants had abnormal conditions of the eyeball. The power of overcoming
hypermetropic defects possessed by the very young eye in virtue of the extraordinary elasticity of
the crystalline lens is well known, and is well demonstrated by the case recorded by Dr. Macdonald
in which the child was able under exceptional stimulus to attain a visual acuity of 6/6 in spite of the
fact that it possessed such a very grave defect as 7 dioptres of hypermetropia in one diameter and
11 dioptres in another.
In regard to the difficulties produced by the necessarily rough results which are given by the
tests of visual acuity which it is possible to use in school inspection, Dr. Cowell reports the frequency
in his experience with which masked or latent defect is recorded during school inspections in children
suffering from passing illness. Such children when in their usual health readily pass the tests, but
after an attack of influenza or similar illness are temporarily incapable of reading the smaller
denominations of type.
Comparing boys with girls as tested with the Snellen types it is seen that the vision of boys is
considerably better than that of girls, and the difference is more marked at the higher age. It has
been frequently pointed out that the reason for the larger percentage incidence of defective vision in
girls, particularly at older ages, is very probably due to the less hygienic conditions of training
in respect to vision to which girls are subjected both at school and at home. A more detailed analysis
is given of the vision of 5,843 of the 13,179 cases of children aged 12 in class 3 (vision or worse in
either or both eyes). The analysis relates to children aged 12 (i.e., born in 1901) examined during
the first term of the year in the schools in the Boroughs of Hampstead, Holborn, Islington, City of
London, Stepney, Shoreditch, Bermondsey, Lambeth, Wandsworth, Camberwell, Deptford, Greenwich,
Lewisham and Woolwich.
A comparison between the two eyes shows that it only rarely occurs that there is a great
difference between the visual acuity of either eye taken separately. The visual acuity of the right
eye is greater than the left in a few more instances than those in which the left proved to be the
better eye. Of the 2,731 boys whose vision was analysed the vision was found to be better than 6/24 in
the right eye in 2,040 cases and in the left eye in 2,009 cases. Both eyes were better than 6/24 in
1,683 cases. Among girls the corresponding figures for the 3,112 cases analysed were, right eye,
2,355 ; left eye, 2,289 ; both eyes, 1,991.
The difference between the vision in the two eyes in individual cases is shown from the
following summary of vision of these 2,731 boys and 3,112 girls.
Both eyes alike. Right eye worse. Left eye worse.
Boys 1,032 (37.8 per cent.) 846 (31.0 per cent.) 853 (31.2 per cent.)
Girls 1,371 (44.1 per cent.) 810 (26.0 per cent.) 931 (29.9 per cent.)

Good 6/6 86 %
Fair 6/12 and 6/9 10 %
Bad 6/6 and less 3 %