Explain the structure and functioning of the human eye. How are we able to see nearby as well as distant objects?

(N/A) The human eye is a complex organ that functions like a camera. Its main parts are:
$1$. Cornea: The thin membrane covering the front of the eyeball,which acts as the primary refractive surface.
$2$. Iris: $A$ dark muscular diaphragm that controls the size of the pupil.
$3$. Pupil: The aperture that regulates the amount of light entering the eye.
$4$. Crystalline Lens: $A$ transparent,flexible lens that focuses light onto the retina.
$5$. Ciliary Muscles: Muscles that change the curvature and focal length of the lens.
$6$. Retina: The light-sensitive screen where the image is formed.
$7$. Optic Nerve: Transmits visual information from the retina to the brain.
Functioning and Power of Accommodation:
The ability of the eye to adjust its focal length to see objects at varying distances is called the power of accommodation.
- To see distant objects: The ciliary muscles relax,making the lens thin,which increases its focal length.
- To see nearby objects: The ciliary muscles contract,making the lens thicker,which decreases its focal length.