354 



GENERAL SCIENCE 



to be its closer conformation to the shape of the eyeballs. This is 

 untrue. 



Protect the Eyes. Too much light, as well as too little, should 

 be avoided. A " soft " light of sufficient strength to afford easy 

 vision without fatigue to the eyes is the ideal illumination. 



Avoid severe contrast. For example, a brilliant light against a 

 dark background is injurious to the eyes. 



Bad position; light shining in 

 the eyes, direct reflection 

 from book, chest contracted. 



FIG. 235. 



Good position; eyes shaded, 

 no reflection from the paper, 

 chest expanded. 



Lamps should be so placed or shaded as to prevent the eye being 

 exposed to bright light sources. 



The source of light should never be in front of a person who is 

 reading. The light should fall over the shoulder or come from the 

 side. 



Lamps should be so placed or shaded that the rays falling on a 

 glazed or polished surface will not be directly reflected into the eyes. 

 Books with very shiny paper surfaces often produce injurious effects 

 by reflecting too much strong light into the eyes, 



