Report of the council of the British Medical Association on the efficient control of railway servants' eyesight.

Date:
[1892]
Catalogue details

Licence: Public Domain Mark

Credit: Report of the council of the British Medical Association on the efficient control of railway servants' eyesight. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    panies nse it ; it is not improbable that its adojDtion has been due to tb.e fact that it represents a certain Government standard of vision. As a matter of fact, however, these dots were designed by Prof, (now Sir Thomas) Loirginore in 1860 for a special pur- pose, namely, “ For ascertaining if a recruit could see a 3 ft. bull’s-eye at 600 yards—but not to test the nature of refraction or other visual defects.” These dots, when used at 15 ft., at best can only demonstrate that a man has one-fourth of the average power of sight. The method is further open to this grave objection that many persons with faulty focussing power (refraction) can in youth by muscular effort overcome the focal difficulty, but as life advances are unable to do so. The rate of failure is proportionate to the amount of the focal defect, but depends also on the muscular strength, and is modified by states of health and exposure of the eyes. Thus, a lad of this class may count dots at 15 ft., but if he is over-fatigued or out of health his sight may fail him at a critical moment, and without the aid of glasses it will certainly be considerably less acute by the time be has reached five-and-thirty or forty years of age. By proper methods of examination applied by persons prac- tically conversant with them, there is no difficulty in determin- ing pr’ccisely the transparemey, the focal structure, and the condition of the nerves of the eye, and an unhesitating opinion can be given not only as to the pr-esent, but also the probable future, fitness of the individual for the employment he seeks. Defects of vision depending on errors of refraction are much more frequent than cases of colour-blindness. We cannot leave this part of the subject without mentioning that mor'o than one case has come under our notice in which men who have passed the tests of an important railway Com- pany have voluntarily resigned, confessing that their sight was unequal to the requirements of engine drivnig, thougli capable of passing the gross test applied by the ofiicials. It is needless to say that the temptation to conceal the defect is very strong, and is not always resisted. (3) It will be observed that the test FOR COLOUR sense on 15 Plnglish I’ailways, on neaily all the Scotch and more than half the Irish lines, consists simply in naming coloured objects. The fallacy of such a method of examination is as certain as it is hard to impress on the lay mind. As Pi’of. Holmgren long ago pointed out, it is often worse than no test, since it may license that which it should prevent, and instead of convincing a man of his defect, induces in him the contrary belief because evc7i a colour-hliiul person sometimes names colours correctly. We are convinced that the method of testing the colour sense of rail- way servants by merely ascertaining if they can name certain colours is quite inadequate for the purpose, and is fraught with grave possibilities of danger to the public. ^ On the other hand while we are of opinion that Holmgren s principle must form the basis of every reliable method of testing for the colour sense, we recognise, every ex- perienced examiner must admit that its application requires an amount of experience and training rarely met with among laymen, and only acquii’ed by medical men who have ha special instruction and have devoted some time to the stmly of the subject. It must not therefore he taken for granted that all