The common eye defect that occurs in old age is .......

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

Iodopsin is associated with .......

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

Analogy type question:
$(1)$ Photoreceptor cells : Cones : Dim light vision : ........
$(2)$ Eyeball contains transparent crystalline : Lens : : In front of the lens : .........

The retinal blood vessels enter the eye at