What is range of vision ?

Explanation

The range of vision of a person is the distance between near point (N) and far point (F) of his eyes. The point at closet distance, at which an object can be seen clearly by the eye is called near point (N) of the eye.
The most distant point at which an object can be seen clearly is called far point (F) of the eye. For a normal eye, far point lies at infinity. Therefore, for a person with normal vision, the range of vision is infinite.