Mr. Brudenell Carter read an interesting paper on Wednes- day,
before the Society of Arts, on "Vision-Testing." He said that the methods pursued on the English and Scotch railways and by the Board of Trade for testing colour-blindness are wholly untrustworthy, and that Holmgren's test of colour- blindness by using different shades of wool is the only adequate test, and that even that is only adequate when Holmgren's own rules are strictly observed. About 3-95 per cent.,—or, say, four in every hundred,—are colour-blind, and it is essential that these colour-blind persons should not be employed as engine-drivers or look-outs at sea, when a mistake in seeing the colour of a lamp displayed may involve a fearful calamity. In the discussion which followed, Dr. Edridge Green disputed the statement that the Holmgren test is the right one for engine-drivers and sea- men. "Those who were colour-blind could be instructed so as to pass it, while normal-sighted persons might fail by a confusion of colours." He preferred the lanthorn to the Holm- gren test. Mr. Brudenell Carter, in reply, held that in the testing of the cases referred to by Dr. Green, some of Holm- gren's rules had been neglected ; but he asked Dr. Green to submit his case to the Royal Society, and offered to test personally the cases where, in Dr. Green's opinion, the Holm- gren test had failed. No one maintained that the tests of colour-blindness adopted in England are adequate.
Previous page
