742 POPULAR SCIENCE MONTHLY. 



will be found no muscle in the body which can endure continuous con- 

 traction except for a short time. Tests of holding the arm out 

 straight, carrying a light satchel in one hand, etc., are familiar. Most 

 muscles called into continuous action show that the continuity is an 

 interrupted one, and that there are necessary rhythms of contraction, 

 relaxation and rest. The genius of evolution, so far as the eye is 

 concerned, never foresaw the demands to be made upon the organ by 

 our modern life. In but one or two hundred years since printing, 

 urbanization, commerce and the rest have sprung into existence, the 

 entire process, ocularly speaking, has been reversed; before this it 

 was an intermittent and temporary function, while that of reading, 

 writing, sewing and handicrafts demands a focussing of the image of 

 objects at twelve or fifteen inches from the eye; this for millions has 

 now become a continuous one. For all hyperopic and astigmatic eyes 

 the act of accommodation is required for ten or fifteen hours a day, 

 often for hours with hardly a moment's interruption. This unwonted 

 demand requires the continuous innervation and contraction of the 

 ciliary muscle. To comply necessitates an impossible task, considered 

 physiologically ; the result is eyestrain with its host of sequent diseases, 

 far-away reflexes, headaches, nervous diseases and kinds of ill-health 

 too numerous to enumerate. 



If the hyperopia were alone present, and especially if the amount 

 were alike in each of the two eyes, cerebral ingenuity could cope with it 

 with far less disastrous results than are everywhere shown. The eyes 

 are seldom alike and the evils multiply. But they become genuinely 

 morbid with the complication of the usually-present astigmatism. 



The ciliary muscle is a ' sphincter muscle/ fashioned in a circular 

 manner about a central point, and by its very nature it must act by an 

 equal, or comparatively equal, contraction of all its parts. Astig- 

 matism is a defect acting in a line across the structure, and hence to 

 neutralize or compensate, the ciliary muscle is called to act against 

 its structure and nature upon two opposite sides, those parts at right 

 angles not acting. Hence the impossibility of overcoming the defect, 

 at least in but a limited and partial, and always unnatural, way. The 

 higher the astigmatism the greater the limitation and impossibility. 

 In the high degrees it is frankly out of the question, and the retinal 

 together with the sensation-making function is hurt by the false and 

 blurred image, and vision deteriorated. ' The old ophthalmology,' 

 still ruling unquestioned in Europe and largely everywhere, looks upon 

 the correction of astigmatism by glasses only as a means of giving 

 better vision, and so corrects only the large errors. It forgets that in 

 these large optical defects the ciliary muscle renounces effort, and 

 that the smaller ones are precisely those which produce the worst 

 morbid results, because the strain of accommodation, or continuous 



