Myopia is due to

$A$ person cannot see distinctly at a distance less than $1 \, m$. Calculate the power of the lens that he should use to read a book at a distance of $25 \, cm$.

$A$ man can see clearly up to $3 \, m$. Prescribe a lens for his spectacles so that he can see clearly up to $12 \, m$.

$A$ student studying the similarities and differences between a camera and the human eye makes the following observations:
$I$. Both the eye and the camera have convex lenses.
$II$. In order to focus,the eye lens expands or contracts while the camera lens moves forward or backward.
$III$. The camera lens produces upside down real images while the eye lens produces only upright real images.
$IV$. $A$ screen in a camera is equivalent to the retina in the eyes.
$V$. $A$ camera adjusts the amount of light entering in it by adjusting the aperture of the lens. In the eye,the cornea controls the amount of light. Which of the above statements are correct?

$A$ person has a near point of $50 \, cm$ and a far point of $3 \, m$. What power of lens is required to $(i)$ read and $(ii)$ see distant stars?

$A$ person cannot see objects clearly beyond $2.0 \, m$. The power of the lens required to correct his vision will be: