Show EYE HAS GREAT sensitivity wonderful human organ capable of adapting itself to any possible circumstances on entering a lark dark room after a stay in the outside daylight the eye at once begins to increase in sensitivity at first this increase appears to he be slow but alter after five minutes the increase Is quite rapid the eye acquiring a sensitivity several hundred throes its initial value after 30 mn utes sojourn in the dark the sensitivity still increases hut but more slowly than before and after 45 minutes or an hour the maximum sensitivity Is reached the final sensitivity varies slightly with different dIr ferent people but in fully adapted condition the eye Is easily or times more sensitive than it was at the beginning these facts are obtained from a 8 study of the sensitiveness of the eye in the dark made by selig hecht of crelghton creighton university omaha and published in the journal of general physiology mr hechtl study goes to show that the increased sensitiveness Is due to a reversible teal leal reaction within the retina involving a photosensitive substance and its two products of decomposition |