How does it possible to get the image at the same distance on the retina ?

Explanation

When the eye is focussed at distant object, the ciliary muscles are relaxed. So the focal length of eye lens adjusted itself which is equal to the distance of object from the retina. Then we can see the object clearly.
When the eye is focussed on a closer object the ciliary muscles adjust th focal length in such a way that the image is formed on retina and we see the object clearly.