338 HELPS IN LESSON PREPARATION 



about the dangers to the eye from wood alcohol and 

 substances made from it. 43. Why may patent medi- 

 cines, Jamaica ginger, etc., injure the eyes? 44. State 

 why one should avoid using a towel that persons having a 

 disease may have used. 45. Why is plenty of sleep good 

 for the eyes? 46. Tell the estimate Dr. Cohn makes in 

 regard to one thousand cases of blindness, page 249. 



47. State why concave glasses correct nearsightedness. 



48. Tell how school children often bring on nearsightedness. 



49. Describe the experiment in regard to nearsightedness 

 which the German government made. 50. Give some 

 good evidences of farsight. What kind of glass corrects 

 farsight? 51. To what is astigmatism usually due? 

 How may it be recognized, page 254? When neither 

 concave nor convex glasses correct the eye's defect, what 

 is usually the difficulty? 52 What is the usual cause of 

 squint or cross-eye? Tell why it should be immediately 

 attended to. 53. Mention some warnings of the fact that 

 our eyes probably need glasses to correct some defect. 

 54. Give some good reasons why it is very foolish for chil- 

 dren not to wear glasses when they have some defect of 

 vision. 55. Why are spectacles better than nose glasses? 

 56. Relate the experience of Francisque Sarcey. 57. In 

 all eye tests, why is it important to keep one eye covered 

 while the other is being tested ? 58. Why should the ques- 

 tion of expense not delay us in having our eyes treated 

 by an oculist? 59. Give some good rules to guide us 

 daily in the use of our eyes. 60. State how weak eyes 

 may be benefited. How may defective eyes be cor- 

 rected ? 



