On Light in some of its Relations to Disease. 165 



victim of chorea, but of late a sufferer from intense neu- 

 ralgia, and from that distressing form of headache called 

 hemicrania, was found to have astiscmatism in a hiorh de- 

 gree ; and her only son, a boy sixteen years of age — who 

 is, like his grandfather and nncle, a subject of headaches, 

 recurring so frequently as to interfere with his educa- 

 tion — is, like his mother and uncle, astigmatic. I might 

 mention some scores of family histories, of which these 

 are fair examples. 



We are all aware of the fact of this inherited tendency 

 to disease, and yet no person in his senses supposes that a 

 disease like epilepsy or neuralgia is directly transmitted 

 from one generation to another; and this subject of here- 

 ditary tendency has always been one of the great mysteries 

 of medical science. But facial features are directly trans- 

 mitted from parent to child; and, if the form of the eye 

 can constitute an important cause of a class of diseases, 

 the hereditary tendency to these diseases, if it exists, is 

 readily explained. 



It would be of little service to a person suffering from a 

 nervous affection to assure him that he had an astigma- 

 tism or an hypermetropia, or that be was unequally myopic 

 in the two eyes, unless science offered a relief to these un- 

 pleasant peculiarities. Fortunately, modern science is 

 fully prepared to afford the relief demanded. 



During the last few years, under the leadership of men 

 of the highest genius, like Prof Bonders, of Utrecht, a 

 class of medical men has brought the science of correcting 

 anomalous refractions of the eye to a perfection which is 

 truly wonderful. Formerly, when a person reached the 

 age of forty-five or fifty, and found that he was, in the 

 language of a medical friend, " forced to trombone his 

 newspaper " in order to find the least uncomfortable dis- 

 tance at which to hold it, sought the nearest jeweler, 

 bought a pair of spectacles which seemed nearest right, but 



