There are three major components of the eyes: the eyelids, the lens, and the retina. The majority of our vision occurs within the perimeter of our eyes. All of these components work together to assist you to see well. First, light enters the iris (the transparent front layer of your eye). The iris (colored portion of the lens) controls the amount of light that the pupil permits into the retina.
The final component is the retina. The retina is the thick, fibrous tissue that extends from the back of the eyes all the way to the back of your head. It acts as the receiver of information for the eyes. The main article below describes the main functions of each component.
In order to understand how the eyes work, it helps to understand the function of each major component. The retina receives visual information from light and causes the main part of your eye to move. In order for the retina to work properly, the iris must remain closed during all stages of your vision. However, sometimes the iris will become partially open or even fully open. This is called hyperopia or astigmatism.
The sclera, the white covering of the sclera, controls the size and shape of the eyeball and determines how much vision the eyeballs can take in. It also plays a big part in determining the color of the eyes. There are three major sclera muscles that allow the sclera to move, they are the external hemorrhoid muscle, the internal cephalothoracic muscle, and the fundus luteum. These six muscles play an important role in keeping the sclera closed in a person suffering from a wide variety of eye problems, including Astigmatism. As we age, the eyes tend to lose strength in these areas, and this weakening can cause the eyeball to move out of alignment.
The central vision cones are located in the center of your eyes, these are called the macula. They allow the eyes to focus on a nearby object by moving the optical systems to a central point. Two eyes are perfectly capable of focusing on a distant object; when either eye focuses on a distant object it is called monocular distortion. This problem usually occurs with older individuals who tend to have smaller modular sizes.
The third major component of your retina is called the rod and cone cells. These two sets of cells allow your eyes to distinguish colors and determine movement in visual environments. When colored object moves in front of you turn your head to look at the object, your brain sends signals to the optic nerve to perform a process called ocular reflex.