How does it help to see objects at long distances and short distances ?

A norml eye is unable to see objects at a distance less than distance of distinct vision. If is because

A norml eye is unable to see objects at a distance less than distance of distinct vision. If is because

Ability of the eye to see objects at all distances is called

Ability of the eye to see objects at all distances is called :

Some people cannot see objects at long distance, but can see near objects clearly What is his vision defect ?