The retina of eye contains two types of light receptors: cones and rods. These cells receive and organize visual information. Cornea is the clear outer layer at the front of the eye. It helps the eye to focus light so the vision is clear. Iris is the colored tissue at the front of the eye that contains the pupil in the center. The iris helps control the size of the pupil to let more or less light into the eye.Lens of an eye is a curved structure that bends light and focuses it for the retina to help see images clearly.