Question

What changes take place in the shape of eye-lens: 

 when the eye is focused on a near object?

Answer 1

When the eye is focussed on a nearby object, the eye lens bulges and becomes thicker. This is because, when the eye is focussed on a nearby object, the ciliary muscles of the eyes contract, loosening the suspensory ligaments attached to the the eye. As these ligaments become loose, they stop pulling the eye lens, because of which the eye lens bulges (or becomes more convex) so as to increase its converging power.