How powerful our eyes are, though on average the size of the eyeball is only about an inch in diameter and weighs around 0.25 ounces, 80% of sensory information our brains receive is from the eyes. Human eye works much like a digital camera. Light is primarily focused by both the cornea and the crystalline lens then reaches the retina which acts as an electronic image sensor of a digital camera, converting optical images into electronic signals. The optic nerve then transmits these signals to the visual cortex- the part of the brain that controls our sense of sight. Amazingly, they allow us to see 10 million colors. However, many abuse and neglect their eyes.