The image formed on the retina is:

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

$A$ person's near point is $50 \, cm$ and his far point is $3 \, m$. The power of the lenses he requires for $(i)$ reading and $(ii)$ seeing distant stars are:

$A$ person with hypermetropia has a near point of $60\, cm$. What power of lens should be used for the eye to read a book at $25\, cm$?

The far point of a myopic eye is $250 \, cm$. What is the focal length of the lens required to correct this defect?

If the distance of the far point for a myopia patient is doubled,the focal length of the lens required to cure it will become