EYESTRAIN. 745 



brain steadily innervate a muscle to continuous contraction. There 

 results eyestrain — an error, the result of an error, the consequence of 

 an older error; all may be done away with by an easily-obtained, at 

 present usually unobtainable, device. The obtaining of that device is 

 a matter of more importance to civilization than all the universities and 

 wars of the last century. ' Exaggeration ? ' Not so ! 



For what are the consequences of eyestrain? Wherever there is 

 eye-labor ' at near-range,' as in reading, writing, sewing, mechanics, 

 art, science, commerce, etc., there, beyond question in one half the 

 workers, is eyestrain of a disease-producing kind. What kinds of 

 diseases ? 



Firstly, those of the eye itself, for surely all good oculists agree 

 that a large majority of local eye-diseases are themselves directly or 

 indirectly due to eyestrain. The only exceptions are albinism, loss of 

 accommodation generally (presbyopia), some tumors and a few minor 

 affections. Cataract, it is being recognized, is due to the morbid func- 

 tion of denutrition set up by the strain to neutralize errors of refrac- 

 tion, and may be prevented by wearing correcting spectacles long prior 

 to the ' cataract age.' Almost all other inflammations of the eye, not 

 excepting often the infectious ones, are usually due to the same morbid 

 function. Function, as all good physiologists know, always precedes 

 structure, and malfunction, as all good physicians know, also precedes 

 the morbid and fatal organic pathology. Eyestrain is almost always 

 the cause of eyes turning in, or out, that is, squint or strabismus, a 

 trouble that is ' innervational in nature and refractional in origin.' 



The next of the series of bad results of eyestrain are cerebral. The 

 brain comes out to see, but owing to the enormous difficulty of the task, 

 it sees poorly and with exhausting or irritating labor. As its every 

 process and act is bound up with and the product of vision, visual dis- 

 orders by reflex and passed-on malfunction induce cerebral affections, 

 evidenced primarily by headache, migraine, etc. Although the medical 

 text-books give little or no hint of this, it is true, as thousands of good 

 physicians and patients well know, that headaches, ninety per cent, 

 at least, are due to eyestrain. Many observant physicians believe that 

 the so-called ' paroxysmal neuroses,' periodic headaches, migraine, epi- 

 lepsy, asthma, etc., as well as hysteria, neurasthenia, ' brain-fag,' ' ner- 

 vous breakdown ' are very frequently caused by years of morbid ocular 

 struggle. 



Mental diseases follow : weariness, alternating with hyperexcitability, 

 an amazing need of walking, truancy (escaping from ocular labor), 

 morbid introspection, nameless torments and self-tormentings, diseased 

 habits, hopelessness, melancholia, manias, incipient and functional in- 

 sanities and indirectly occupational failure, crime and many other 

 errant trends. 



The methods by which morbid ocular function induce various bodily 



