260 Physiology. 



5. Reading Heavy Books. Do not hold the book or 

 work nearer the eyes than is necessary. So far as possible 

 avoid continuous reading in large or heavy books by arti- 

 ficial light. Such books being hard to hold, the elbows 

 gradually settle down against the sides of the body, and 

 thus the book is held too close to the eyes, or at a bad 

 angle, or the body assumes a bad position. 



6. Resting the Eyes. Frequently rest the eyes by 

 looking up and away from the work, especially at some 

 distant object. One may rest the eyes while thinking over 

 each page or paragraph, and thus really gain time instead 

 of losing it. 



7. Strength of Light. Have light that is strong enough. 

 At twice the distance from a lamp the light is only one 

 fourth as strong. Reading just before sunset is not wise. 

 One is often tempted to go on, not noticing the gradual 

 fading of the light. 



8. Evening Reading. Do the most difficult reading by 

 daylight, and save the better print and the books that are 

 easier to hold for work by artificial light. Writing is usu- 

 ally much more trying to the eyes than reading. By care- 

 fully planning his work one may economize eyesight. 

 Weak eyes, by proper care, may outlast and do more work 

 than those naturally stronger, but injured by abuse. Read- 

 ing before breakfast by artificial light is usually bad. 



9. Reading during Convalescence. Many eyes are 

 ruined during convalescence. At this time the whole sys- 

 tem is weak including the eyes. There is a strong 

 temptation to read, perhaps to while away the time, per- 

 haps to make up for lost time in school work. This is a 

 time when a friend may show his friendship. 



