We know that if an object is lying at a distance more than the focal length of a convex lens,its real and inverted image is formed on the other side of lens.The image through the eye and camera is formed in the same way.Let us compare the structure and function of both of them.
CAMERA. camera is a kind of box to which q convex lens is mounted on the front side.The lens form a real and inverted image of an object on a sensitive image film placed behind it.A system is provided in a camera to move the lens back and forth so that Sharpe image is obtained on the film. There is shutter behind the lens that remains close normally.When the button is pressed the shitter is open for a while light coming from the object enters the camera during this intervals an image is firmed on film. The amount of light enters the camera depending upon the size of aperture. Aperture is an opening in the diapharam behind the lens.This can be made smaller or larger as required. The pictures is obtainer by developing the image on thelens.HUMAN EYE. The human eye also work like a camera.The eye is almost a sphere of diameter about 2.5cm.Its outer boundary called the sclera is thik and hard.At the front of eye there is a trasparrent hard skin known as cornra. Behind the cornea there is iris and after that there is convex lens.The inner layer of the back wall of eye is called retina.The retina of eye and the films of camera serve the same purpose.Like camera,the eye lens form a real and inverted image of the object on retina.The optic nerve carries it on the form of signals to the brain. Although the image for end on retina is inverted but our brain interprets this correctly,i e ,the right way up.The iris acts like the diaphragm of camera.The opening at the center of iris is called pupil which is just like aperture of a camera.when the light outside is dim, the iris contracts to make the pupil largers so that more light can can enter the eye.In bright ligt, the irices makes the pupil smaller.
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CAMERA. camera is a kind of box to which q convex lens is mounted on the front side.The lens form a real and inverted image of an object on a sensitive image film placed behind it.A system is provided in a camera to move the lens back and forth so that Sharpe image is obtained on the film. There is shutter behind the lens that remains close normally.When the button is pressed the shitter is open for a while light coming from the object enters the camera during this intervals an image is firmed on film. The amount of light enters the camera depending upon the size of aperture. Aperture is an opening in the diapharam behind the lens.This can be made smaller or larger as required. The pictures is obtainer by developing the image on thelens.HUMAN EYE. The human eye also work like a camera.The eye is almost a sphere of diameter about 2.5cm.Its outer boundary called the sclera is thik and hard.At the front of eye there is a trasparrent hard skin known as cornra. Behind the cornea there is iris and after that there is convex lens.The inner layer of the back wall of eye is called retina.The retina of eye and the films of camera serve the same purpose.Like camera,the eye lens form a real and inverted image of the object on retina.The optic nerve carries it on the form of signals to the brain. Although the image for end on retina is inverted but our brain interprets this correctly,i e ,the right way up.The iris acts like the diaphragm of camera.The opening at the center of iris is called pupil which is just like aperture of a camera.when the light outside is dim, the iris contracts to make the pupil largers so that more light can can enter the eye.In bright ligt, the irices makes the pupil smaller.
