COLOUR BLINDNESS

Hokitika Guardian, 13 August 1932, Page 7

COLOUR BLINDNESS

THEORIES AND REMEDIES. RESEARCH IN BRITAIN. The Physical and the Optical Societies of Britain arranged a joint discussion on vision recently. Leading British and foreign physicist, physiologist, and psychologists met at the Imperial College of Science and Technology, and contributed some thirty papers on the subject, The discussion was very largely concerned with colour vision. Inasmuch as everything that we see is coloured, there is some difficulty, from the general point of view, in explaining how such a large variety of colours can exist. Tli© three-colour process of reproduction shows, however, that it is possible to reproduce all visible or recognisable colours by the blending ol these three,

From the scientic point of view, it was gathered that there is also a difficulty in relating the events that occuri'n the retina of the eye to the possible occurrences of three fundamental colour sensations. Various explanations are offered, but it is not yet possible to say exactly what mechanism underlies these processes. The general opinion seems to be that the presence of three processes must be related to normal colour vision.

Certain people are defective in colour vision, and it appears in their case as if one of these three sensations is absent. A common defect, for example, is a certain degree of inability to distinguish between red and green.

Although the point was not made in the discussion, optical authorities regard it a.s unfortunate that street signals for motor-drivers do not combine shapes, which all could distinguish, with colours, to which over 4 per cent, of men are blind The Ministry of Transport have had this difficulty brought to their notice by the British Medical Association.