Segment 1 Opening credits. A man is seen doing various activities: shaving in the morning, reading a newspaper, working at a desk and playing tennis. The narrator says that during all these activities his eyes are constantly adjusting. A plastic model eye is seen, then overlaid with an illustration of a cross section of an eye, seen from the side. Labels show the cornea, iris, pupil, lens, retina and optic nerve as the narrator explains their functions. A photographic camera is seen as the narrator explains the similarity between the way cameras and eyes work. An animation shows what happens when a camera views an object and photographs it. On the back of the camera, the inverted object is seen in the viewer. The photographer adjusts the lens to focus the image. An animation shows the eye muscles adjusting to alter the eye's lens. A person enters a darkened cinema auditorium; the light adjusts to show their eyes adapting to the dark. Various activities that strain the eyes are seen: watchmaking, welding, driving and office work. A man tries to read a page but the text is blurry; he is long-sighted. Long-sightedness and short-sightedness are explained using animations. An illustration of the blood circulatory system of the body is seen; the narrator explains that poor eyesight is sometimes an indicator of health problems, not just of bad eyesight. A woman goes to see an optician, and the narrator stresses that everyone who has eye problems should go to an eye doctor, as sometimes the problem may be more serious than just needing glasses. Time start: 00:00:00:00 Time end: 00:07:36:10 Length: 00:07:36:10