22 



Dr. T. L. Llewellyn. 



[Dec. 19, 



Observations on Pigmentation. 

 Early in my investigation I noticed that several of my severe cases had 

 hlue eyes and fair hair. The possibility of a partial albinism suggested 

 itself, and I took notes of all cases. Nettleship (25), in his Bowman lecture 

 and elsewhere (26), suggests that congenital nystagmus may be due to a 

 partial albinism confined to the eyes. 



Table XXI. — Showing Colour of Hair and Eyes in Nystagmic Cases. With 

 each colour eye three sets of figures are given ; the first refers to fair-, the 

 second to medium-, and the third to dark-haired people. 



Blue 62, 61, 47, eyes only noted, 15, total 185 j Qr ^ cent 



Blue-grey and grey.. 15, 25, 32 „ 1, „ 73 J 



brown 6 > 13 > 17 ; •• ; 36 } 142, or 35-5 per cent. 



Dark brown 3, 43, 53, eyes only noted, 7, total 10G J 



Table XXII. — Control Test, Adult Miners, same District. 



Blue 59 > 76 > 57 > total 192 } 272, or 41-97 per cent. 

 Blue-grey and grey 13,17,50, „ 80 J 



Light brown 5,70,43, „ 118 j 3?6 ^ 



Dark brown 5, 53, 200, „ 258 J 



Table XXIII.— Colour of Hair. 



Nystagmus. Control. 



Fair 86 }228 82 }298 

 Medium 142 i 216 J 



Dark 149 350 



Relation of Nystagmus to Accident. 

 In 76 cases there was a distinct connection between the onset of the 

 disease and an accident. The accident was to the head in 33 cases, to the 

 eyes in 28, and to the body in 15. I have no space at present to quote cases. 

 I am also convinced that nystagmus predisposes to accident, but the subject 

 is such a difficult one that I am unable at present to give any figures. 



5 of Nystagmus. 



The patient should be asked to fix the finger tip held about 12 inches in 

 front of and on a level with the eyes. If movement does not appear, 

 gradually elevate the finger, asking the patient to follow. Note the degree 

 above the horizontal at which movement begins ; this gives a rough test of 

 the severity of the disease (Eoniiee (1)). 



If this fails ask the patient to stoop or exert himself. The eyes may be 

 examined in a mirror held under the patient's head while he remains in a 



