Abstract
Problems of Colour Vision. Colour vision and colour blindness are of much importance in connexion with signal and traffic lights and navigation, as well as being of general interest. Between the colour ‘normal’ and the actual colour-blind, many intermediate states exist, and a review of literature dealing with colour discrimination by Mr. W. O'D. Pierce has recently been issued by the Medical Research Council (Special Rep. Series, No. 181. London: H.M. Stationery Office). The Committee on the Physiology of Vision of this Council has also undertaken at the request of the Admiralty investigations on the subject which are now published in another report (Special Rep. Series, No. 185. London: H.M. Stationery Office). A surprising number of colour-sense defectives may be found even among men who have been selected after passing colour-vision tests now in general use, and in some of these cases the defect may be present in such degree as to impair efficiency. Thus, in harbour the colour of moving navigation lights may be correctly interpreted by colour-defectives by contrast with known fixed ‘key’ lights, while moving lights at sea are misnamed. Coloured lights of high intensity may be correctly named when the same lights of low intensity cannot be recognised. The red end of the spectrum may be visually shortened compared with the normal-a dangerous defect- and so on. The report lays down the requirements for an effective system of tests, and recommends those for the Navy, namely, the Ishihara card test first, followed by a lantern test, preferably with the Board of Trade lantern. No single test is infallible.
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Research Items. Nature 132, 935–937 (1933). https://doi.org/10.1038/132935a0
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DOI: https://doi.org/10.1038/132935a0