The least distance of distinct vision for a young adult with normal vision is about ...... $cm$.

$A$ person with a myopic eye cannot see objects beyond $1.2\, m$ distinctly. What should be the type of the corrective lens used to restore proper vision?

$A$ person needs a lens of power $-5.5$ dioptres for correcting his distant vision. For correcting his near vision he needs a lens of power $+1.5$ dioptre. What is the focal length (in $cm$) of the lens required for correcting distant vision?

What is the far point and near point of the human eye with normal vision?

The human eye can focus on objects at different distances by adjusting the focal length of the eye lens. This is due to

Make a diagram to show how hypermetropia is corrected. The near point of a hypermetropic eye is $1 \, m$. What is the power of the lens required to correct this defect? Assume that the near point of the normal eye is $25 \, cm$.