Is there any limit to change of focal length of eye lens ?

What changes the focal length of the eye lens?

From the given figure, what is the focal length of eye lens ?

Name the part of the eye : (a) which controls the amount of light entering the eye. (b) on which the image is formed. (c) which changes the focal length of eye-lens.

What are the maximum and munimum focal lengths of the eye lens ?