Solution:

A cataract is a dense, cloudy area that forms in the lens of the eye.

A cataract begins when proteins in the eye form clumps that prevent the lens from sending clear images to the retina.

The retina works by converting the light that comes through the lens into signals. It sends the signals to the optic nerve, which carries them to the brain.

Aging is the most common cause.

This is due to normal eye changes that happen starting around age 40.

That is when normal proteins in the lens start to break down. This is what causes the lens to get cloudy.

People over age 60 usually start to have some clouding of their lenses.