The fovea centralis is located in

The second cranial nerve in humans originates from:

Select the correct option based on the given sentences regarding the mechanism of vision:
$(I)$ Light rays in the visible wavelength are focused on the retina through the cornea and lens.
$(II)$ It generates impulses in rods and cones.
$(III)$ Photosensitive pigment is composed of an opsin (protein) and retinal (an aldehyde of vitamin $A$).
$(IV)$ Light induces the dissociation of retinal and opsin.
$(V)$ This process causes a change in membrane permeability,as a result,potential differences are generated in the photoreceptor cells.

Which pigment is present in the rod cells that is useful for vision during the night?

Which structure of the eye is involved in focusing the eye?

The lens of the eye and the retina are developed from which embryonic germ layer?