Explain how a normal human eye is able to see distinctly the object placed at a distance as well as those placed at a nearer distance. What is the far point and near point of a normal human eye?
For seeing distant objects, the focal length of the eye lens should be large and for seeing near objects the focal length of the eye lens should be small.
The focal length of the eye lens can be adjusted with the help of ciliary muscles holding the lens in position. The far point and near point are at infinity and at 25 cm respectively.