An eye can focus the images of the distant objects as well as the nearby objects on its retina by changing the focal length ( or converging power ) of its lens.
The ability of human eyes lens to focus the distant objects as well as the nearby objects on the retina by changing the focal length ( or converging power ) of its lens is called accommodation.
A normal eye has a power of Accommodation which enables objects as far as infinity and as close as 25 cm to be focused on the retina.
Range of vision of a normal Human eye :
Far point : the farthest point from the eye at which an object can be seen clearly is known as the "far point" of the eye. The far point of the normal human eye is infinity
Near point ( distinct vision ) : The minimum distance at which an object must be placed so that a normal eye may see it clearly without any strain is called the least distance of distinct vision. The least distance of distinct (clear) vision for a normal Human eye is about 25 centimetres.
The range of vision of a normal Human eye is from infinity to about 25 centimetres.