296 Report of the Committee on Colour- Vision. 



Board of 

 Trade tests 

 for colour- 



Naming 

 colours, a 

 defective test. 



the present time. Allowing" for those whose colour-vision has 

 been found defective by the inadequate tests used, and who 

 may not be afloat, it is certain that out of the 120,000 seamen 

 who are employed, there must be a large number who are colour- 

 defective, and consequently a source of danger to life. The 

 statistics of the examinations of eyesight on railways, so far as 

 they have come before the Committee, are eminently unsatis- 

 factory. Although candidates for employment are occasionally 

 rejected for defective colour-vision, yet the percentages of the 

 rejections on different railways differ widely from each other, 

 and from the average percentage of colour-blindness of the male 

 population. The evidence taken on this subject points to these 

 differences being due to the variation in efficiency of the tests 

 employed, and the Committee have been forced to the conclusion 

 that some men, whose vision is defective for colour and for form, 

 are in all likelihood employed in positions where normal vision is 

 essential for public safety. 



The evidence, moreover, points to the fact that steps have not 

 hitherto been taken (at least, as a rule) in judicial inquiries 

 relating to the causes of accidents, to ascertain whether they 

 were due to defective vision. The Committee are strongly of 

 opinion that in cases of collision or accident, where the evidence 

 is conflicting as to the recognition of a coloured light, witnesses 

 should be examined both for colour- and form-sense. 



The Committee have had before them evidence regarding the 

 colour- vision testing of the marine service as laid down by the 

 Board of Trade. 



Tests may be divided into two classes : one dependent upon 

 the correct naming of a colour, and the other on its correct 

 appreciation. The first class are intended to combine with the 

 detection of colour-blindness that of colour-ignorance, or the 

 defective knowledge of the names of colours. The last class 

 are intended to detect colour-blindness alone, colour-ignorance 

 being independently tested. The tests which the Board of 

 Trade have officially adopted, are described in Appendix 

 II. The examination consists in requiring the examinee to name 

 correctly the colours of cards by day-light, and of coloured 

 glasses by lamp-light. The correct naming of the colours is 

 alone insisted upon. 



The Committee consider that the tests themselves and the 

 method of applying them are necessarily open to very grave 

 objection. The Board of Trade test cards and coloured glasses 

 can be procured from dealers, and the Committee have no hesitation 

 in saying that the colours may be correctly named in the testing 

 room by colour-blind persons after a certain amount of instruc- 

 tion, which would consist in teaching them to distinguish the 

 different cards or test glasses by their different luminosities. 

 The glasses are red, pink, three kinds of green, yellow, 

 neutral, standard blue, and pale blue, all of which are viewed 

 by artificial light, usually that of an oil lamp. In trials made 



