The principles of health control . Fig. 56. — The Muscles of Accommodation and of Fusion. A. The muscle which is overworked in ciliary strain. B. Themuscles that become exhausted in fusion strain. of the extreme convergence of the eyes from viewingobjects so very near, and in all cases in which there mustbe a continual readjustment of the eyeballs, such asoccurs in reading on moving trains and in viewing movingpictures. The strain which results from a day of shop-ping or of sight-seeing is usually fusion strain. The strainwhich results from overwork of the eyes at close rangewhen there are no
The principles of health control . Fig. 56. — The Muscles of Accommodation and of Fusion. A. The muscle which is overworked in ciliary strain. B. Themuscles that become exhausted in fusion strain. of the extreme convergence of the eyes from viewingobjects so very near, and in all cases in which there mustbe a continual readjustment of the eyeballs, such asoccurs in reading on moving trains and in viewing movingpictures. The strain which results from a day of shop-ping or of sight-seeing is usually fusion strain. The strainwhich results from overwork of the eyes at close rangewhen there are no focusing defects, or when the defectsare properly corrected with glasses, is in most cases fusionstrain. Indications of Eyestrain. — Indications that the eyemuscles are being overworked, or strained, are of two 258 PRINCIPLES OF HEALTH CONTROL kinds — local indications which are observed upon theeyes themselves and indications that result from irritationand exhaustion of the nervous system. The local irrita-tions include pai
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecthygiene, bookyear1920
