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The Causes and Prevention of Miners' Nystagmus. 

 By T. Lister Llewellyn, M.D., B.S. (Lond.), Tyndall Research Student. 



(Communicated by Dr. J. S. Haldane, F.R.S. Eeceived December 19, 1911, — 

 Read February 22, 1912.) 



CONTENTS. 



PAGE 



Description and Physical Signs of Miners' Nystagmus 10 



Frequency 12 



Cost to the Country 13 



Historical Account of the Disease and of Theories of its Causation ... 14 

 Conditions Determining its Occurrence — 



Age and Duration of Underground Work 16 



Nature of Occupation 16 



Thickness of Seam 17 



Lights Used 18 



Ocular Defects 20 



Pigmentation of Eyes and Hair 22 



Connection with Accidents 22 



Diagnosis 22 



Prognosis 23 



Causation 23 



Preventive Measures 25 



Acknowledgments of Assistance 25 



References to Literature 26 



Miners' nystagmus is an occupational neurosis which is confined to workers 

 in coal mines. The chief symptom and physical sign is a rotatory oscillation 

 of the eyeballs, which prevents the miner from accurately fixing anything 

 towards which his vision is directed. The result may be compared to a 

 cinematograph exhibition, in which the pictures have not been taken rapidly 

 enough to produce a continuous image, or where the film has been worn 

 away by over-use, giving a blurred image. 



Description. 



The man first notices that he is unable to perform the more skilled part of 

 his work; he cannot notch timber well, and fails to drive his wedge, or 

 strike with his pick the exact piece of coal aimed at. He next complains 

 that the lamps dazzle his eyes, that he is unable to see anything at night 

 time, and, finally, that the lamps and all surrounding objects are going round 

 and round. Headache, varying from slight pain between the temples to 

 attacks of extreme severity, giddiness on exertion and stooping, night- 

 blindness, dread of light, and in severe cases marked nervous depression (two 



