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                     The Human Eye

It is a sensitive sense organ that acts like a camera, enable us to capture the colourful  pictures of the surroundings.
It forms a real image on it's light sensitive surface retina.
 
                   Parts of Human Eye

  • Cornea  :  It is a thin membrane through which light enters. It forms the transparent bulge on the front of eyeball. Most of the refraction occurs at the outer surface of the cornea.

  • Eyeball :  It is approximately spherical in shape, with a diameter of 2.3 c.m. 

  • Iris :  It is a dark muscular diaphragm that controls the size of pupil. It is behind the cornea.

  • Pupil :  It regulates and control the amount of light entering in the eye . It is the black opening between aqueous humour and lens.

  • Crystalline Eye lens :  Provide the focussed real and inverted image of the object on the retina. It is composed of a fibrous , jelly like material. This is convex lens that converges light at retina.

  • Cilliary muscles :  It helps to change the curvature of eyelens and hence changes it's focal length so that the object clearly placed at different position.

  • Retina :  Thin membrane with large number of sensitive cells . Here formation of image takes place.
         When image is formed at retina, light sensitive cells gets activated and generate electric signal. These signals are sent to brain via optic nerve. Brain anylyse these these signals after which we perceive object as they are.


                



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