"The main cause of myopia is to be found in the very conditions under which children are gathered together in schools: insufficiency of light, the over-small type common in school-books, the frequent use of the blackboard, on which the teacher is not always careful to make the size of the characters he traces proportionate to the distance at which they have to be read, are so many causes of ocular fatigue. The visual keenness of a given eye, says Doctor Leprince, decreases rapidly when the intensity of the light falls below a certain limit. The pupil, working with insufficient light, repairs the defective keenness of which this is the cause, by increasing the visual angle under which the details of the object he is looking at appear to him; in other words, _he brings that object inordinately close to him_. "The time necessary to recognize a given letter increases greatly, when the limit of visual acuteness has been reached. Therefore, insufficient light would tend to make work slower, unless the pupil increased acuteness by approaching the object more closely. Thus myopia constitutes a positive adaptation to the defective conditions of work, enabling the pupil to work more rapidly." [6] [Footnote 6: Bronardet and Mosny, _Hygiene Scolaire_. Boilliere, Paris, 1914, pp. 142, 143, 430, 496.] It would seem therefore natural to say: let the child find himself a better lighted place; if the blackboard is at some distance from him, let him come nearer to it; if the insufficient light retards his work, let him go more slowly; if the questions at issue are such harmless things as changing a place, advancing a step or two, taking a few minutes longer over a task--what tyrant on earth would deny such a small favor, and condemn the suppliant to blindness? Such a tyrant is the teacher, who aspires to win the affection of his victims by means of moral exhortations. It would be so simple to allow children, when tired of sitting, to rise, and when tired of writing, to desist, and then their bones would not be twisted. Who can look on unmoved at the spectacle of children whose vertebral column is being deformed by using desks, just as in the Middle Ages the instep was deformed by the torture of the boot. And on what grounds is this odious torture judged to be necessary? Because a man has substituted himself for God, desiring to form the minds of children in his own image and likeness; and this cannot be done without subjecting a free creature to torture. This is the only reason. We will now quote the remedies by means of which a so-called science proposes to counteract spinal curvature in school-children. It has determined the exact position in which a child may remain seated and at work for a long period of time without injury to the vertebrae.