Remarks on colour blindness / by P. Cullen.

  • Cullen, P.
Date:
[1882]
Catalogue details

Licence: Public Domain Mark

Credit: Remarks on colour blindness / by P. Cullen. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    the exemption of the above races may be due to their having dark hazel irides is not borne out by my examinations. Neither is Dr. C. Roberts’ statement (Lancet of 21s£ January, 1882), that the colour of the hair of the different tribes examined by him in Ame- rica seemed to influence this affection, or that fair-complexioned nations, with light-coloured eyes, are those which suffer most from colour blindness. In each of the 969 individuals I noted the colour of the eyes. Among the 430 railway servants I found 203 had dark hazel irides, 140 light hazel, 56 black, 28 grey, and 3 blue; all the blues and greater number of the greys were in Euro- peans, and about one-fourth of the black in Eurasians. Of the fifteen affected with colour blindness nine were dark hazel and six slight hazel. Among the children there were:— Boys. Girls. Dark hazel 212 18 Light hazel ... ... ... 209 40 Black 44 10 Brown ... ... ... 6 O and of the twelve boys affected eleven had dark hazel and one light hazel irides. Thus, although the eyes examined were 543 dark and 426 light, the affected were 20 dark to 7 light, or nearly in the proportion of three to one. It will be interesting to know the experience of other Indian Surgeons on this point, which seems opposed to that of observers in Europe. That colour blindness has no effect on the vision is admitted by all, but few perhaps are aware of the number of natives who suffer from myopia. In my examination of railway employes I have to test the strength of vision also, and among the 430 railway men examined—after excluding several who had lost one eye; others with cataract, &c.—I found 35 who were myopic, some of whom could read only No. 20 test type at 5 and 8 feet distant; others, uneducated, who counted No. 12 test dots at 4 and 8 feet; while the distant vision, for large objects, of many extended to only 50 to 80 yards. But of the colour blind, only one man was myopic, and he was very much so, as he could only read No. 12 type at 4 feet, and his distant vision did not extend over 50 yards. Among