The sclera, also known as the white of the eye, is the opaque, fibrous, protective, outer layer of the eye.
The iris is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupil. The color of the iris is often referred to as "eye color."
The pupil is a hole located in the center of the iris that allows light to enter the eye. It appears black because light rays entering the pupil are either absorbed by the tissues inside the eye directly, or absorbed after diffuse reflections within the eye that mostly miss exiting the narrow pupil.
The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. The cornea, with the anterior chamber and lens, refracts light, with the cornea accounting for approximately two-thirds of the eye's total optical power.
The crystalline lens is a transparent, biconvex structure that, along with the cornea, helps to refract light to be focused on the retina. By changing shape, the lens functions to change the focal distance of the eye so it can focus on objects at various distances.
The retina is a light-sensitive layer of tissue, lining the inner surface of the eye. It captures light sent through the cornea and crystalline lens to create an image by triggering nerve impulses that pass to various visual centers of the brain via the optic nerve.
The macula and fovea are small areas within the retina that contain rods and cones to determine the color and shape of the image you are viewing.