Random Thought #74

Why is it that you can't immediately see when you go from a lit situation to a dark situation and vice versa? I thought I knew the answer, but in simple terms. The more scientific reason is kinda interesting. Wikipedia says "Pupillary response is a physiological response that varies the size of the pupil, either resulting in constriction[1] or dilation (expansion), via activation or deactivation of the iris dilator muscle. The response can have a variety of causes, from an involuntary reflex reaction to exposure or inexposure to light — in low light conditions a dilated pupil lets more light into the eye — or it may indicate interest in the subject of attention or indicate sexual stimulation.[2] The pupils contract immediately before someone falls asleep." I knew about letting in more light or less light into the eye but the others were new to me. I'm not sure how more light enables us to see in darker scenarios but its amazing how the body automatically reacts to certain stimuli. Quite fascinating.