12 



Dr. T. L. Llewellyn. 



[Dec. 19, 



accompanied with drooping of the upper eyelids and convergence of the eyes. 

 I regard this sign as one of extreme importance. 



The eyes are often congested, and a convergent squint is frequently found. 

 The power of fixation and accommodation is greatly weakened. The patient 

 tires very quickly, and the visual acuity may drop from normal to half 

 of normal in a few minutes. When movements are present, vision is rarely- 

 more than one-sixth of the normal. 



Table III. — Frequency of the Disease. 



Per cent. 



Eomiee (1) and Nuel (4) 20 



Dransart and Famechon (5) 10 



Court (1890) (6) 34"75 of coal cutters. 



Stassen (3) 21*7 



Libert (7) 239 



Eogers (8) 17 "5 



All these figures are obtained by systematic examination of several 

 thousands of workmen. 



My figures refer not to the total number of cases of nystagmus, but to the 

 number of men who were compelled to give up underground work for a time. 



Table IV. 



District. 



Cases. 



Underground workmen. 



A 



425 



133,000 



B 



413 



56,580 



C 



27 



8,000 



D 



11 



28,000 



E 



75 



12,500 



P 



2 



2,870 



G 



1 



6,855 



H 



No known cases 



5,437 



G- and H are naked-light districts, F is an anthracite district. B, C, D are almost entirely- 

 safety-light districts in which a considerable amount of holing is done. A is largely a safety- 

 light district in which holing is the exception. 



I am obliged to Dr. S. W. Plummer, of Durham, for notes of 10 cases 

 which have come under his notice as certifying surgeon for his district. 

 Dr. Plummer is unable to give me the proportion this number bears to the 

 number of men employed, but as the cases are spread over a year the amount 

 of nystagmus, at present, in the North of England appears to be small. 



In the Blue books (ref. 9, 10, 11) on " Statistics of Compensation/' 

 the number of cases of nystagmus receiving compensation for the years 1910.., 



