How many types of cones are present which are responsible for the colour differentiation?

Which of the following is not correct for rods?
$(I)$. Twilight vision is the function of the rods
$(II)$. It is responsible for daylight vision sometimes
$(III)$. The rods contain a protein called rhodopsin
$(IV)$. Rods are photoreceptor cells
Choose the correct option

The space between the cornea and the lens is called .....

The following figure is a diagram showing parts of the human eye. Identify $P, Q$,and $R$ from the options given below.
$\quad\quad P\quad\quad\quad Q\quad\quad\quad R$

Vitamin $A$ is necessary for the proper physiological function of the eye because

Which of the following is not a part of the human eye?