The eye is the sense organ that enables us to see the world around us. Both the eyes are connected through a pair of optic nerves to the occipital lobe of the brain. As we age, some of the protein of the lens starts clumping together which clouds a small area of the lens. This prevents light from properly passing through it. This is cataract, and over time, more of the protein clumps to cloud larger areas of the lens, making it harder to see.