One of the organs which is most commonly strained in modern life is the eye. In its modern use, the eye is constantly focusing at a short distance. To look at the horizon is a rest. The reflex evils from eye-strain are great and numerous and are often incorrectly ascribed to entirely different causes. Headaches, nausea, and dizziness are especially frequent results of eye-strain. Probably some of the breakdowns in middle life are due primarily to the reflex effect of eye-strain. Eye-strain is to be prevented by scientifically adapted spectacles, by care to secure the right kind of illumination, and in some cases by systematically resting the eyes. Reading on moving trains or looking for a long time at moving pictures may overstrain the eye. One should be especially careful not to read in a waning light or, on the other hand, to read in the glare of the sun. If one works facing a window, it is advisable to wear an eye-shade; otherwise there is a struggle between the tendency of the bright light to close the pupil and the tendency of the work requirement to keep it open. To offset the evils of a sedentary life, it is advisable to spend one hour daily, or at least 15 minutes, in some kind of vigorous physical exercises. [Sidenote: Mechanical Home Exerciser] The rowing-machine is probably the most beneficial form of mechanical home exercise that is likely to be followed faithfully. Simple stretching in bed when one wakes up is helpful, especially if combined with breathing exercises. [Sidenote: Stimulating Heart and Lungs] The most beneficial exercise, as a rule, is that which stimulates the heart and lungs, such as running, rapid walking, hill-climbing and swimming. These should, of course, be graduated in intensity with varying age and varying degrees of vitality. [Sidenote: Exercise after Meals] Gentle muscular activity after meals promotes normal digestion and should be practised for a quarter or half an hour after each meal, but violent exercises immediately after meals should be avoided, as a large amount of blood is then engaged by the digestive system. [Sidenote: Outdoor Exercise in Winter] A very important fact for the average man to take into consideration is that, whereas he naturally gets considerable out-of-door exercise in summer, he allows it to lapse in the winter. Such a decided change in the amount of exercise is dangerous and should be avoided by taking regular gymnasium exercise. Even though a gymnasium is not elaborately equipped, use can be made of such games as hand-ball, volley-ball and other available games. [Sidenote: Enthusiasm in Exercise]