This is the first of a two-part series on human sense organs to be followed by 'The Ear.' Due to the efforts of bio-research and the modern development of photography and television, we are beginning to understand how the human eye works. Television in many ways parallels how the eye operates. From its crude beginnings with photocells and rotating discs, the first successful TV broadcast was by the British Broadcasting Corporation at the coronation of KIng George VI in 1937. This was followed in the US by NBC's televising of the New York World's Fair in 1939. From these beginnings the industry boomed with 1 million receivers in 1949, 10 million receivers in 1952, and 50 million by 1959.
Television involves a camera which converts the image into an electronic signal. The TV color camera is a very complicated mechanism in which light is focused on a series of mirrors. Each mirror is composed of special glass that reflects one color and transmits all other colors. The first mirror reflects only red and transmits blue and green; the second mirror reflects blue and transmits green. These three primary color images are reflected by their respective mirrors onto three separate orthicon tubes. The electronic signals from these tubes are modulated onto three radio carrier waves of different frequencies. When these waves reach the receiver, they are demodulated and each produces an electron beam in the picture tube. These three beams are focused at an angle of 120 degrees from each other onto the phosphorescent face of the tube. The phosphorescent screen is composed of 600,000 phosphor dots arranged in triangular trios composed of a red dot, a blue dot, and a green dot at angles of 120-degrees. As each phosphor dot is struck by a beam, it glows in the corresponding color, and the three images blend together into a color picture.
This description of how a television system works may seem complicated, but I have just given a very simplified picture of the intricate details involved. However, television pales in comparison to the structure and function of the human eye and the sensation of sight. The eye is a complex light-tight, spherical camera. Light enters through the transparent cornea, then through a circular opening, the pupil, and is focused by the lens onto a light sensitive layer, the retina, In the retina are about 75-150 million cells called rods and about 7 million cells called cones. The rods detect black and white while the cones detect colors, lines, and shape. These cells are connected to the visual center of the brain by a cable of some 1.2 million neurons called the optic nerve. How the brain converts the neural impulses into sight is still a mystery. When one considers the complexity of vision, and the mysteries still unsolved, one is constrained to agree with David that we are indeed "fearfully and wonderfully made."
