The choroid is thin over the posterior two-thirds of the eyeball,but it becomes thick in the anterior part to form the:

Match List-$I$ with List-$II$ with respect to the human eye.

List-$I$	List-$II$
$A$. Fovea	$I$. Visible coloured portion of eye that regulates diameter of pupil.
$B$. Iris	$II$. External layer of eye formed of dense connective tissue.
$C$. Blind spot	$III$. Point of greatest visual acuity or resolution.
$D$. Sclera	$IV$. Point where optic nerve leaves the eyeball and photoreceptor cells are absent.

Choose the correct answer from the options given below:

What is the ciliary body?

What is rhodopsin present in the rod cells?

Perception of colour is possible among

Label the following parts in the given diagram of the human eye:
$(a)$ Aqueous chamber
$(b)$ Cornea
$(c)$ Lens
$(d)$ Retina
$(e)$ Vitreous chamber
$(f)$ Blind spot.