Sight
in physiology, one of the five human senses, having for its organ the EYE (q. v.). In this organ, then, we have August, 1902. nerve, to receive and transmit to the brain the impressions of light; certain refractthe retina, an expansion of the optic light traversing them as to throw a correct image of an external body on the retina; and a contracting diaphragm, with central apertures ures for regulating the quantity of light admitted into the eye. When the eye is directed to any object, an image of that object is depicted on the back of the eye by means of the rays of light entering the pupil, and duly refracted by the different humors. The image, which the eye is directed to any object, an image of that object is depicted on the back of pression on the retina with the assistance of the choroid coat, and this impression passes inward to the nervous centers, whence the optic nerve takes its rise. The subject of binocular vision, or that with two eyes we only perceive one object, was long a perplexing subject to philosophers, passes inward to the nervous centers, means of that now well-known instrument the STEREOSCOPE (q. v.).
The power of adapting the eye to vision SIGISMUND lly entertained is that it deat different distances has received the pends mainly on some alteration, either most varied explanations; but the opinion in position or form, which takes place in on in a very now generally the crystalline lens. Some persons possess this power of adaptation slight degree, and thus labor under defective vision, of which there are two ing power of the eye, and so causes the image of an object to be formed at a point anterior to the retina, and is remby anything-such as undue convexity of the cornea-which increases the refracting power of the eye, and so causes the image of an object to be formed at a point anterior to the retina, and is remedied by the use of concave glasses. verse of this, and is remedied by the use of convex glasses, which diminish the other hand, is owing to conditions the reverse of this this, and is remedied by the use partly from the motion of its image over focal distance of an image formed in the eye. We judge of the motion of an object partly from the motion of its image over the surface of the retina, and partly from the motion of our eyes following it; and of the form of bodies, partly from the mere sensation, and partly from the association of ideas.
In law, bills of exchange are frequently sentation), or a certain number of days "after sight." In the last case the time begins to run from the period of present. ment and acceptance. "Sight draft" and "Sight bill" are bills payable at sight.