It must be remembered, however, that although this adaptation takes place so perfectly and without any apparent difficulty, it requires an expenditure of Innate force to accomplish this action. If the change takes place too rapidly from a soft light to an intense light, without sufficient time for adaptative action to take place, the delicate structure of the eye will be damaged by the violent light vibrations. The change from the soft rays of the moonlight to the intense illumination from the bright sun takes place gradually. First, the night; next, the gray dawn of morning; and then comes the sun, whose rays are softened as they pass through a maximum amount of atmosphere near the horizon, and as the sun approaches the dome of the arc, the rays become more intense, since they pass through less of the earth’s atmosphere. Then the process is reversed as the intense light from the sun gives way to the softer rays from the moon. This gives Innate plenty of time to bring about the adaptative processes so necessary to adjust the eye to these extremes, time being a very important factor in all the processes of the body. Thus it is appreciated that the subject of lighting is important from a hygienic standpoint, since improper lighting necessitates an unnecessary expenditure of energy and causes impaired health. The Eye That we may better appreciate this adaptability and have a clearer understanding of the mechanism through which Innate Intelligence accomplishes this adaptative action we will review briefly the organ through which we perceive light—the human eye. The eye consists of a crystalline lens, powerfully refractive, held between two transparent liquids called the aqueous humor, which is in front of the crystalline lens and the vitreous humor, which is behind or posterior to the crystalline lens. The aqueous chamber is divided into an anterior and posterior chamber by the diaphragm called the iris, through which is an opening called the pupil, permitting communication between the chambers of the aqueous humor. The retina, which is composed of nervous tissue, lines the posterior five-sixths of the inner surface of the posterior wall of the eyeball. At the back of the retina and in the direct visual axis is a spot known as the macula lutea, a yellow spot, in the center of which is a depression known as the fovea centralis. At this point the vision is clearest and it is this spot used when we turn our eyes and look directly at an object. With such a delicate instrument as the eye it is only reasonable that special care and arrangement should be supplied to protect it from sudden changes in the intensity of light. Otherwise the eye would be greatly injured by the glare of light. This adaptation is accomplished by means of regulating the amount of light admitted to the retina. This is done through the expression of Innate by regulating the size of the pupil.