In the human eye,the focusing is done by:

The light when enters the human eye experiences most of the refraction while passing through

$A$ person uses a lens of power $+3 \text{ D}$ to normalize vision. The near point of the hypermetropic eye is ....... $m$.

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

The least distance of distinct vision of a long-sighted person is $60 \ cm$. By using a spectacle lens,this distance is reduced to $12 \ cm$. The power of the lens is

$A$ 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?