Report of the Committee on Colour-Vision. 341 



In the ordinary examination the candidate would be told to 

 point out all the colours on the board. We find it necessary to 

 state to the candidates that there are four simple colours — no 

 crimsons, oranges, or violets. 



In case a candidate fails to name correctly the colours on the 

 board, we satisfy ourselves further by using the wool test. The 

 men who are going to be examined have no access whatever to the 

 test board, and to vary the positions of the colours we turn the 

 board round. We carry our tests much farther in the case of 

 officers, particularly naval cadets and engineer students, who are 

 required to haveabsolute normal vision and colour vision, each being 

 examined separately by Snellen's test, supplemented by flags and 

 wools. They stand at a distance of 16 feet, and are shown each of 

 the flags separately, and have to name them in quick succession, 

 tested with either eye. That is the first test, and the next is 

 Mr. St. Clair Buxton's marine telechrome. [The Witness exhibited 

 this apparatus, and explained its use.] The glasses in this lantern 

 are used at the same distance as the flags (16 feet), with red, blue, 

 violet, green, and white lights in quick succession, and with the 

 fogging apparatus, which is simply a piece of glass fogged on 

 one side^ with no lens whatever. Supposing a candidate mistakes 

 between red and green, we take a further test. The candidate 

 is allowed to wait while the rest of the examination is proceeded 

 with, and is then re-examined on the doubtful point, as it is 

 absolutely necessary that an executive officer should discern at 

 once every coloured flag, either of our own or foreign nations, 

 In several cases the Medical Director-General has allowed a 

 young" gentleman to come up a second time for examination one 

 or two days later, but I have looked through the records and 

 find they are never successful when once defective colour percep- 

 tion has been detected. 



The figures giving the proportion of candidates rejected are as 

 follows: — In 1888 there were 214 examined for Naval Cadetships, 

 and of those, one was rejected for inability to distinguish greens 

 from browns, and another was found ignorant of the names of 

 colours. It appears, however, in the records that upon being 

 examined subsequently the same day he was passed. In 1889, 

 out of 293 examined, there were 1-02 rejections for defective 

 colour perception. Of these one was rejected for confusing greens 

 and browns ; one was absolutely colour-blind ; and one in the 

 immediate perception of colours was uncertain. In 1890, 305 

 naval cadets were examined, the percentage of rejections being 

 1*31. Of these one was rejected for inability to distinguish 

 between greens,reds, and browns ; and three were rejected for being 

 unable to distinguish green from red. These were boys whose 

 parents had received the warning as to defective sight ; but, as a 

 rule, parents do not care to go to the expense or trouble of a 

 medical examination beforehand by their own doctor. 



Although I have laid great stress upon promptness in replying- 

 to the questions in examination, we do not reject candidates for 



