That defective vision is beginning to interfere with the activities of men, is shown by the fact that in many instances, in later times, colour tests have been required to determine fitness of applicants for positions in various departments of commercial enterprise. In this country, during the last fifty years, much attention has been given to the subject of visual defects in seamen, railroadmen, and other persons occupying positions of responsibility in which unimpaired vision is an important qualification. In response to a request sent by the German Government through its minister to the Surgeon-General of the United States Army, for statistical and other information on the subject of colour-blindness, Mr. Charles E. Pugh, General Manager of the Pennsylvania Railroad, in September, 1884, sent to William Thomson, M.D., surgical expert for the same company, the following statement:
Total number examined on lines east of Erie 25,158 Colour-blind 481 Defective vision 661
The apparently small percentage of colour-blind in this table may be ascribed to the non-application of men who knew their deficiency, and to the fact that men in the service, knowing their defect, would leave the road before examination, and thus escape detection, and be enabled to gain employment on other roads where no examinations are required.[38]
[38] _Pop. Science Monthly_, vol. xxxi., p. 796.
In several departments of the national government, attempts have been made to guard against the dangers resulting from imperfect sight. In the examination of recruits, the War Department at Washington, some years ago, issued orders that bits of coloured pasteboard, or “test cards” be used for determining the power of individuals to distinguish objects at a distance, while worsteds of various hues were employed to ascertain their ability to distinguish colour. In the Treasury and Naval Departments were ordered similar examinations, in which the power to distinguish colour was a necessary qualification in the case of all persons seeking employment therein.
In the examinations ordered by navigation and railroad companies to protect themselves and the public against disaster resulting from imperfect vision in their employees, tests have been made. Among the requirements imposed by law, applying to engineers, brakemen, and firemen, in the State of Connecticut, are the following: “Unobstructed visual field, normal visual acuteness, and freedom from colour-blindness.”