EYE STRAIN 261 



do not, frequent and severe headaches occur as a result of too 

 great muscular effort toward accommodation. Among young 

 people headaches are frequently caused by overexertion of 

 these muscles. Glasses relieve the muscles of the extra ad- 

 justment, and are effective in eliminating this cause of headache. 



An exact balance is required between glasses, crystalline 

 lens, and muscular activity, and only those who have studied 

 the subject carefully are competent to treat so sensitive a part 

 of the body as the eye. The least mistake in the curvature of 

 glasses means an improper focus, increased duty for the muscles, 

 and gradual weakening of the entire eye, followed by headache 

 and general physical discomfort. The oculist therefore must be 

 carefully trained for his work. 



Eyestrain. The extra work which is thrown upon the 

 nervous system through seeing, reading, writing, and sewing 

 with defective eyes is recognized by all physicians as an impor- 

 tant cause of disease. The tax made upon the nervous system 

 by the defective eye lessens the supply of energy available for 

 other bodily use, and the general health suffers. The health is 

 improved when proper glasses are prescribed. 



Possibly the greatest danger of eyestrain is among school 

 children. For this reason, many schools employ a physician 

 who examines the pupils' eyes at regular intervals. 



The following general precautions are worth observing : 



1. Rest the eyes when they hurt, and as far as possible do 

 close work, such as writing, reading, sewing, or wood carving 

 by daylight. 



2. Never read in a very bright or a very dim light. 



3. If light is near, have it shaded. 



4. Wear an eye shield if the light produces a glare. 



5. Do not rub the eyes with the fingers. 



6. If the eyes are weak, bathe them in lukewarm water in 

 which a pinch of borax has been dissolved. 



