Question

why we are not able to see clearly the objects placed closer than 25 cm

Answer 1

Because it is the minimum distance from which one can clearly see things otherwise closer than that , everything will get blurry.


Edit: the lower one is right according to science and stuff.

Answer 2

This is because the ciliary muscles of eyes are unable to contract beyond a certain limit. If the object is placed at a distance less than 25cm from the eye,then the object appears blurred because light rays coming from theobject meet beyond the retina.