Rhodopsin (visual purple) present in the rods is a derivative of $......$.

Which of the following statements are correct for the iris?
$(I)$. The ciliary body extends forward to form the iris.
$(II)$. It is a pigmented and opaque structure.
$(III)$. It is the visible coloured portion of the eye.
Choose the correct option.

What is the light-sensitive chemical present in the human eye composed of?

The middle layer of the eye is covered by which type of epithelium?

$X -$ Rod cells' function is twilight (scotopic) vision.
$Y -$ Cone cells' function is daylight (photopic) vision.

The human eye is most sensitive to light of wavelength: