The function of the iris is to ....

In $presbyopia$:

The retina of nocturnal birds contains:

Which of the following are functions of the cone cells of the retina?
$1.$ Photopic vision
$2.$ Colour vision
$3.$ Scotopic vision

The aqueous chamber,which is filled with aqueous humour,is the space:

Following are various structures/regions of the human eye. Choose the correct option with respect to the sequence of the passage of light for the formation of an image:
$(A)$ Cornea
$(B)$ Lens
$(C)$ Aqueous humor
$(D)$ Pigment epithelium of retina
$(E)$ Conjunctiva