What is the role of the pupil in a human eye?

What is the range of vision for a normal human eye?

What is the least distance of distinct vision of a normal human eye (in $cm$)?

What is the muscular structure located behind the cornea in our eye called?

In the eye of a person suffering from myopia (nearsightedness),where is the image of a distant object formed?

$(i)$ What is the least distance of distinct vision for a normal eye?
$(ii)$ Does the above distance increase or decrease for a long-sighted eye (hypermetropia)? Give a reason for your answer with a diagram.