“The eye allows us to see and interpret the shapes, colors, and dimensions of objects by processing light. Light enters the eye first through the clear cornea and then through the circular opening in the iris called the pupil. Next the light is converged by the crystalline lens. The light progresses through the gelatinous vitreous humor to a clear focus on the retina, the central area of which is the macula. In the retina, light impulses are changed into electrical signals and sent along the optic nerve to the occipital (posterior) lobe of the brain, which interprets these electrical signals as visual images.”