Color blindness : remarks / by B. Joy Jeffries at the twenty-ninth annual meeting of the board of the supervising inspectors of steam vessels.

  • Jeffries, B. Joy, 1853-
Date:
[1881]
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Licence: Public Domain Mark

Credit: Color blindness : remarks / by B. Joy Jeffries at the twenty-ninth annual meeting of the board of the supervising inspectors of steam vessels. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

    20/34 (page 18)
    ^'A second visual examination will not he required in any ease^^^ accord- ing to Circular 19. The facts which I have given in reference to acquired color-blindness, from injury, from disease, from alcohol, and from tobacco^ are, I think, sufficient proof of the need of testing the color-sense at least as often as a license is renewed. Most certainly the eyesight, m to form, should be tested as often as that, which, with the testing for color sense, can all be done thoroughly in a few moments by the medi- cal officer of the department, who alone should be intrusted with it. The laity cannot do this, it is a medical examination, for medical men to carry out. I have said that a iDcrson born color-blind dies so, and that it cannot be altered or alleviated. So far, therefore, as congenital color-blind- ness is concerned, one examination would be sufficient; but the ques- tion of acquired color-blindness must never be forgotten or ignored^ and the need of testing for visual power at least once a year is abso- lutely necessary. Ophthalmic surgeons know only too well how grad- ually-failing sight, from cataract or disease, may not be recognized even by the patient himself, and never be known or detected except by their methods of examining the eyes. Incompletely color-blind pilots are, by Circular No. 46, taken out of the hands of the medical officer, and allowed to be tested by the local in- spector with colored signal-lights. The Supervising Inspector-General says, in his annual report: ^'The last circular was issued because it was deemed but a simple act of jus- tice that pilots of many years' exi)erience, without accident of any kind,, should have the fullest opportunity consistent with the public safety to prove themselves competent to continue in the exercise of the duties^ of the profession in which they have been educated. E^ow, the color-blind pilot of the tug Lumberman, who caused the death of ten people and the loss of property, &c., might perfectly well have been just such a case, namely, one that the medical officer would record, in accordance with his instructions, incompletely color-blind, and hence fallen to the local inspector to decide on, who, by the tests he is directed to use, would i3ronounce him perfectly safe to be re- licensed. It is necessary, first, to explain to the board what incomplete color- blindness is. It is to be remembered that the defect exists in all degrees, and none of the Government departments have yet decided the amount permissible in any given case, &c. By referring to page 40 of the United States Manual, it will be seen that Professor Holm- gren proposes to classify the different kinds of color-blindness under especial heads, to be able the better to grasp the whole. He says: We might, indeed, divide this blindness into congenital and acquired ,* but, as we are concerned alone with congenital color-blindness, the division is as follows: I. Total color-blindness, in which the faculty of perceiving colors is absolutely wanting, and where the visual sense, consequently, can only perceive the difference between darkness and light, as Well as the differ- ent degrees of intensity of hght. [Several such cases are lately reported.] II. Partial color-blindness, in which the faculty of certain percep- tions of color, but not of all, is wanting. It is subdivided into— 1st. Complete color-blindness, in which one of the three funda- mental sensations, one of the perceptive organs of color in the retina^