How many eye muscles are present which control all types of eye movement?

An eye is said to be near-sighted when a

Iodopsin is associated with .......

Suppose a person wears convex glasses for proper vision. Where do you think the image of the object is formed in his eyes when he is not using the glasses?

Good vision depends on adequate intake of carotene-rich food. Select the most appropriate option from the following statements.
$I.$ Vitamin $A$ derivatives are formed from carotene.
$II.$ Photopigments are embedded in the membrane discs of the outer segment.
$III.$ Retinal is a derivative of Vitamin $A$.
$IV.$ Retinal is a part of all photopigments that absorb light.

Good vision depends on adequate intake of carotene-rich food. Select the best option from the following statements:
$(1)$ Vitamin $A$ derivatives are formed from carotene.
$(2)$ The photopigments are embedded in the membrane discs of the inner segment.
$(3)$ Retinal is a derivative of vitamin $A$.
$(4)$ Retinal is a light-absorbing part of all the visual photopigments.