Question 2 Compare the eye to a camera by listing four of the basic components of the eye and the equivalent components of the camera. Solution Camera part Function in the camera Structure in the eye performing a similar role Lens To focus light onto the photosensitive surface at the back of the camera. This can either be photographic film or a CCD (charge-coupled device). Lens - which focuses light onto the retina. Focusing screw Allows the user to adjust the focus for nearer or more distant objects. Ciliary muscles - which stretch or slacken the suspensory ligaments to adjust the shape of the lens Aperture Allows the user to adjust the amount of light entering the camera in different light conditions. Iris - which adjusts the amount of light entering the eye through the pupil. Shutter Allows the user to adjust the length of time that light enters the camera, which controls the amount of light to which the photosensitive surface is exposed. Not applicable (although we do have eyelids). .