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 coöperation of the pupil by simple and appropriate physiological 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 otherwise 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 writing-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, "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 transitions from cloud-shadow to sunshine.
8. 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, produces 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-
- "Accommodation and Refraction," p. 419.