=The Local Symptoms of Eye-strain.=—There may be a sense of fatigue in the eyes after reading for a short time, and this may be followed by a constant sense of discomfort in the eyes, which is increased on using them, and which may be accompanied by severe pain in the back of the head. There is a sensitiveness to light, and inflammation of the eyelids and conjunctiva. There may be twitching of the eyelids, and in extreme cases difficulty in keeping the eyes open on account of drowsiness. The eyes may smart, itch, or burn, and continually “water.” As the trouble becomes more pronounced, reading for a short time may be followed by a blurring of the type, and finally the lines may run together. There is a constant sense of the eyes feeling for the lines, and, perhaps one of the first things to call attention to the condition of the eyes may be the losing of the lines in reading. The general or reflex symptom of eye-strain is headache, which frequently takes the form of migraine. This is increased on reading, sewing, riding in the cars, etc. The headache is usually over the region of the temples or just above the eyes, but it may be on the top of the head or at the base of the skull. Vision is so fundamentally related to all the brain functions that eye-strain, or anything which interferes with normal sight, may cause the most varied disturbances of bodily functions. _The Prevention of Eye-strain._—Persons whose work necessitates much ocular labor should vary their duties with intervals of rest. In continued reading or sewing it is well to desist at short intervals and fix the gaze on some distant object, and to frequently close the lids. Lace work, very fine needle work, working on black goods, reading very fine print, or print on an inferior quality of paper, or attempting to read in a dim light, are all a severe tax on the eyes, and should be avoided, as they are certain to cause them permanent injury. Defective vision is so common in school-children, it is so often present without being suspected, and so much harm is done to the eyes and the general health of the individual before it is discovered, that there should be a compulsory law requiring the examination of all school-children; and, again, before boys and girls enter the normal schools and colleges. Clear vision gives clear judgment; defective vision in its various manifestations gives different warps and bents to the mind of their unfortunate possessors. _Veils._—The wearing of veils is responsible for not a little deterioration of vision, particularly when they are thick or dotted. Unless the meshes of the veil are very large, it holds a layer of impure air close to the face, so that the wearer is breathing vitiated air. It hinders clearness of vision, because the external world is viewed through a narrow lattice. The best veil for the eyes is one with a single mesh, either without dots, or the dots so far apart that none shall come over the eyes.