List the Parts of the Human Eye that Control the Amount of Light Entering into It. Explain How They Perform this Function. - Science

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List the parts of the human eye that control the amount of light entering into it. Explain how they perform this function.

 

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Solution

The iris and pupil are the two parts of human eye that controls the amount of light entering the eyes. The iris automatically adjusts the size of the pupil according to the intensity of light received by the eye. If the amount of light received by the eye is large (as during the daytime), then the iris contracts the pupil (makes the pupil small) and reduces the amount of light entering the eye. On the other hand, if the amount of light received by the eye is small (as in a dark room or during night), the iris expands the pupil (makes the pupil large) so that more light may enter the eyes. Thus, the iris regulates (or controls) the amount of light entering the eye by changing the size of the pupil.

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2013-2014 (March) All India Set 3

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