Ans. The imager formation in human eye is shown in the figure. Human eye acts, like a camera. In place of the film, the retina records the picture. The eye has a refracting system containing a converging lens. The lens forms an image on the retina which is a light sensitive layer at the black of the eye. In the camera, the distance of lens from film is adjusted for proper focus but in the eye, the lens changes focal length. Light enters the eye through a transparent membrane called the cornea. The Fig. 12.32 iris is the coloured portion of the eye and controls the amount of light reaching the retina. It has an opening at its centre called the pupil. The iris controls the size of the
pupil while in dim light pupil is enlarged,