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


  1. Class 8
  2. Chapter 16 Class 8 - Light

About the Author

CA Maninder Singh's photo - Founder at Teachoo
CA Maninder Singh
CA Maninder Singh is a Chartered Accountant for the past 11 years and a teacher from the past 11 years. He teaches Science, Accounts and English at Teachoo