8 4 THE POPULAR SCIENCE MONTHLY. 



2. Ignorance or laxity on the part of parents and primary teachers, 

 in permitting faulty positions of the head, body, and book, during 

 reading, study, and writing ; and in not seeking early to secure the 

 intelligent cooperation of the pupil by simple and appropriate physi- 

 ological instruction. 



3. A prolonged and steady looking at an object or at objects near 

 the eye, though at proper distance, without rest or frequent change 

 of the visual focus, as in long and absorbed novel-reading, intense 

 study, or persistent diligence in needlework. 



4. The practice of reading or othei-wise using the sight at too short 

 range. This results in part from insufficient light; or from its faulty 

 direction, so that the hand or body throws a shadow on the page; or so 

 that the direct rays fall upon the eye, causing undue contraction of the 

 pupil, while the page is in shadow. It results also from improperly 

 graded desks, from small and poor type and inferior printing-ink, and 

 from faulty color and quality of printing-paper; also from pale writ- 

 ing-ink pale when used and from the substitution of the lead-pencil 

 for the pen, especially in the evening. 



5. A prone or forward position of the head too long maintained, or 

 frequently repeated, and becoming a habit. This results from reading 

 or studying with the book in the lap, and from the use of desks not 

 graded to the height of the pupil. Dr. Howe reports pupils varying 

 eighteen inches in height seated at the same grade of desks. The 

 distance of the eye from the page should not be less than twelve nor 

 more than eighteen inches. Having the desks set too far from the 

 seats also induces this faulty position. The front of the desk should 

 overlap the seat one or two inches. 



Donders says, 1 " In the hygiene of myopia the very first point is 

 to guard against working in a stooping position." He favors high, 

 sloping desks, and indicates " rectilinear drawing on a flat surface " 

 as a class of work which is especially objectionable. 



6. Since a vitiated atmosphere is a frequent feature of the school- 

 room, it may not be amiss to add here that the effect of bad air is 

 indirectly to injure, if not to destroy, the sight. 



7. Allowing a sun-glare on the page while reading; also transi- 

 tions from cloud-shadow to sunshine. 



S. Reading and studying in railroad-cars is known to be a fruitful 

 source of injury. 



9. But insufficient light, perhaps more than any other cause, pro- 

 duces disease of the eye and derangement of the vision. This is not 

 confined to the schools. Sadly frequent as it is found to be there, it 

 is believed to be yet oftener illustrated at home, both by daylight and 

 in the evening, in preparation for the school and otherwise. Artificial 

 illumination is faulty at best, but, even in the most favored homes, the 

 elder group is apt to monopolize the shaded drop-light or student- 



1 " Accommodation and Refraction," p. 419. 



