What is eye lens and its function?

Mention one function of lens of eyeball.

Reciprocal of focal length in metre is known as the _____ of a lens.

Consider the following statements and select the option which correctly identifies true (T) and false (F).
$\left(\mathrm{i}\right)$ Part that gives colour to the eye is iris.
$\left(\mathrm{ii}\right)$ Transparent outer layer that refracts light is lens.
$\left(\mathrm{iii}\right)$ Retina is a light sensitive layer of the eye.
$\left(\mathrm{iv}\right)$ Cornea is a region without any sensory cells.

The fluid between the retina and the lens is called :

Variable focal length of eye is responsible for :

A human eye can focus objects at different distance by adjusting the focal length of the eye-lens. This is due to

Human eye forms the image of an object at its _____.