$A$ man who cannot see clearly beyond $5 \, m$ wants to see stars clearly. He should use a lens of focal length ....... $m$.

$A$ 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 $25\, cm$?

$A$ far-sighted person has a near point of $60\, cm$. What power lens should be used for eyeglasses such that the person can read a book at a distance of $25\, cm$?

$A$ person can see objects clearly only when they lie between $50\, cm$ and $400\, cm$ from his eyes. In order to increase the maximum distance of distinct vision to infinity, the type and power of the correcting lens the person has to use will be

$A$ man suffering from short-sightedness (myopia) is unable to see objects distinctly at a distance greater than $2\,m$. The power of the lens required to correct this defect should be.......$D$

$A$ 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?