if you look at something a long way off and then near at hand. your pupil gets smaller.
how is this change brought about?

Question

if you look at something a long way off and then near at hand. your pupil gets smaller.
how is this change brought about?

anonymous · Answer

When we're looking at things that are far away, the pupils in our eyes need to grow bigger, to let in more light, so that we can see better. 

But when we're looking at something that is close to us, 
our eyes don't need to let in as much light. 
That's why the pupils in our eyes get smaller.

anonymous · Answer

THIS CHANGE IS BROUGHT BY THE CHANGE IN DISTANCE OF VIEWING AND THE AMOUNT OF LIGHT .