COLOUR BLINDNESS

Hutt News, Volume 19, Issue 11, 15 August 1945, Page 10

COLOUR BLINDNESS

$ No. 214 (By the Department of Health). Colour-blindness is not often acquired. It is only in rare cases that injury or disease of the eye brings on colour-blindness. Most colourblindness is congenital. The condition is hereditary, running down families, usually from a coloui*-blind grandfather, through a normal mother, to a colour-blind grandson. Females are rarely affected, though they are the ones who transmit it. The condition is much more common than people realise. Between 2 and 4 males is every 100 will be grossly colour-blind, and a very much larger percentage will be slightly affected, it is so rare in females that girls are usually not tested l'or the condition. The commonest form of colourblindness is the confusion of red and green. Various tests need to be applied before an individual can be classified as definitely colour-blind. One much used in the past was the Holmgren test, which consisted in matching various ' colour wools. One much used now is the Ishahara test made by reading letters formed by various coloured dots on a background of other dots. Where there's any doubts further tests are available,- but they're the job of an eye specialist. As soon as a boy showfe interest in his future and says definitely what he'd like to be, hiis parents should think whether the calling the boy is going to study or,train for is one that calls for the Absence of colour-blindness. For. cojour-blind-lless is not tested for in Schools in routine medical examinatipns. The confusion of reds and greens would be dangerous in certain occupations —for example, railway feignalman, engine drivers,, sailors. ! The air force pilot or navel man must obviously not be colour-blind; As nothing can be done io change the condition to normal, nuch disappointment is avoided- f colourblind boys are discouraged from training for any occupatioi where the use of colours is involved.