The ability of the eye to see objects at all distances is called

When objects at different distances are seen by the eye,which of the following remains constant?

The image formed on the retina is:

The near point of a person is $75 \, cm$. In order for him to be able to read a book at a distance of $30 \, cm$,what should be the power of the spectacle lenses?

The sensation of vision in the retina is carried to the brain by

For a normal eye,the least distance of distinct vision is......$m$.