334 ILLINOIS STATE ACADEMY OF SCIENCE 



are employed in Illinois. We all know defective vision 

 is a liability. Correct these defects and the procedure 

 would result in increased production, better workman- 

 ship, minimized waste, smaller number of accidents, 

 greater individual comfort and efficiency. 



The economic value of good eyesight to the industry 

 of this country, although difficult to measure, can hardly 

 be overestimated. Careful examination shows that 

 above 60 percent of employes have defective eyes. The 

 fact that this can be almost entirely remedied makes its 

 continuance inexcusable. Frequently a person is found 

 to be practically blind in one eye without being aware 

 of it. A person so afflicted, if injured, may claim com- 

 pensation that is not justifiable. 



Over one hundred years ago Dr. Benjamin Rush, after 

 whom Rush Medical College was named, wrote a book 

 on medical practice, and in the first chapter cites many 

 cases in which patients suffering from rheumatism and 

 other maladies either were cured or greatly improved by 

 the extraction of teeth. 



More than a century ago in England examination of 

 the teeth of school children was considered a routine 

 procedure. 



Teeth of the average adult appear to have been neg- 

 lected, judging from the evidence of 6,000 x-ray pictures 

 taken a few years ago of the mouths of 600 adults of the 

 average age of twenty-eight years. These pictures 

 showed over 1,500 treated teeth and an average of 5y 2 

 teeth missing for each person. Allowing for a few who 

 never had wisdom teeth, we might say that an average 

 of four teeth for each person had been extracted be- 

 cause of neglect of cavities of decay. These same x-ray 

 pictures showed that 51 percent of these 600 adults had 

 infected areas at the ends of roots of one or more teeth, 

 and 53 percent had parts of the bone along the sides of 

 the roots destroyed by the infective process known as 

 pyorrhea. Of the entire 600, 78 percent had one or the 

 other or both types of infection. Nearly every leading 

 physician will tell you that infections of the teeth are 

 by far the most frequent causes of secondary infections 

 elsewhere in the body. The lack of attention to the teeth 



