The focal length of the lens in the human eye is controlled by the:

Iodopsin is associated with .......

In the human eye,the bipolar cells are present in:

Which of the following statements are correct regarding the fovea?
$I -$ The central pit of the macula lutea is called the fovea.
$II -$ The fovea is a thinned-out portion of the retina.
$III -$ The fovea contains densely packed rods.
$IV -$ Visual acuity is highest in the fovea region.

Explain the mechanism of vision in detail.

Label the following parts in the given diagram of the human eye:
$(a)$ Aqueous chamber
$(b)$ Cornea
$(c)$ Lens
$(d)$ Retina
$(e)$ Vitreous chamber
$(f)$ Blind spot.