Iris automatically adjusts the size of Pupil according to the intensity of light.

Hence, the iris controls the amount of light entering the eye by adjusting the size of pupil.


If light is bright, it reduces the size of Pupil,so that less light can enter the eyes

If light is dim, it increases the size of the pupil so that more light can enter our eyes

Function of Iris in dim and bright light - Teachoo.jpg


Adjustment of the size of pupil takes time

If we come from sunlight into a dark room,we are not able to see anything for some time


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Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.