The iris of an eye is an extension of which layer?

Read the following statements with respect to the human eye and select the correct option.
Statement $I$: Uvea is the middle,vascular,and non-pigmented layer of the eye that lies outer to the retina.
Statement $II$: The size of the lens can be adjusted depending on the distance of the object from the eye,through the muscles of the ciliary body and the suspensory ligament.

Which part of the eye controls the amount of light entering into it?

The image is not formed on the blind spot of the retina because...

The light-sensitive chemical substance for vision in mammals is called:

The defective condition of accommodation of the eye in which distant objects are seen distinctly but near objects are indistinct is: