Your eyes are the hardest working parts of your body.
They get to work the minute you open them in the morning and take responsibility for a number of important tasks — from taking in visual cues to transmitting messages to your brain. Your eyes also produce tears that form a thin film over your eyes to protect them from outside interference.
Each eyeball is about the size of a ping pong ball. It rests in a hollowed out spot on the front of your skull, called the socket. Your eyes each are made up of seven basic components:
- Optic Nerve
Though not a part of the eye itself, the eyelid plays an important role in your eye health. It does the blinking for you, keeping your eye clean and moist. Like most of the reflexes that take place in your eyes, blinking occurs automatically. And, of course, your eyelids allow you to block out visual stimulus so that you can sleep. Eyelashes are another ancillary part of your eye — they keep dirt and debris from touching the sensitive areas of your eyes.
The Sclera and Cornea
Serving as the primary covering for your eye, the sclera is the white part that is a tough material forming the shape and surface of the more active parts of your eyes. The sclera, though white at first glance, is filled with tiny red lines, which are blood vessels that carry blood to and from your orbs.
Another exterior piece of the eye is the cornea. This is a thin, clear dome that sits on top of the colored part of your eye. Its primary role is to assist in focusing as light travels through your eyes. Similar to clean, clear glass, the cornea serves as your window to the world of sight.
The Iris and Pupil
The iris is the colorful part of your eye. It’s that ring that designates your eyes blue, green or brown — or some variation of these colors. The iris is the muscular part of your eye in that it controls the opening, or pupil, in your eye to let in an appropriate amount of light. This muscle movement increase or decreases the size of the colorful ring as it adjusts to the level of light.
The pupil is that round black center of each eyeball. It’s actually an opening in the iris. Controlled by the iris, the pupil enlarges or gets smaller according to your visual needs. Surrounding the space between the iris and the cornea, called anterior chamber, is a clear fluid that keeps all the pieces healthy and flowing smoothly.
The Lens, Retina and Optic Nerve
After light passes through your pupil, it hits the lens in each eye. The lens isn’t visible from the outside, which is why it’s so vital to get regular eye exams. The lens is made of a clear, colorless substance that focuses those rays of light onto the back of your eye where the retina lies.
The retina acts like a screen in a movie theater, in that the scenes produced by the lens are played on it. In turn, the retina takes those millions of specks of light and turns them into messages, or nerve signals, that it then sends to your brain for translation. The optic nerve is the main line through which information is processed.
Pulling it All Together
To complete the parts of the eye that make vision possible, you have to give credit to the ciliary muscle inside your eyeball. This muscle changes the shape of your lens every time you look at something different. The vitreous body actually fills the greatest amount of space in your eye. It’s the jelly-like substance that forms the shape of your eyes and takes up two-thirds of the space in each socket.
The retina relies on close to 120 million rods and about seven million cones in each eye. Rods and cones are cells that help you discern color, as well as blacks and gray tones, as messages are processed on their way to the retina. All the components in your eyes, comprised of some two million working parts, coupled with the lubricating tears and protective lid and lashes, work together to provide you with a clear vision of your world.
When Everything Works
Most people give little thought to their eyes when they work well. Eyes are one of the first organs to develop in a fetus, beginning to take shape within two weeks of conception. Interestingly, your eyeballs remain the same size throughout your life. Your skull, ears and nose, on the other hand, continue to grow, which is why your eyes looked so big compared to the rest of your face when you were a child.
Your eyes are the second-most complex organ in your body, after your brain. Yet the average eye weighs only about an ounce, and just one-sixth of your eyeball is exposed. These amazing body parts, which bring the world into view, heal very quickly; a cornea scratch, for example, takes only about 48 hours to fully heal with proper care.
When Darkness Comes
While a damaged socket can be filled with a transplanted eyeball, working eyes cannot be transplanted because of the millions of nerve fibers that connect it to your brain. Regular eye exams and decisive eye correction, repair and restoration are vital to maintain your vision as long as you can. Preventive care is vital for maintaining your vision; the Discovery Eye Foundation reports that 80 percent of problems with vision are either preventable or curable.
The list of eye conditions is long. If you have something as common as astigmatism or age related macular degeneration, you can get treatment. Even if you have something more serious, such asdiabetic eye disease, you should visit your ophthalmologist. If you are having any abnormal visual symptoms, you should always be evaluated with a thorough consultation and examination by a physician for an accurate diagnosis and treatment plan as it may be a symptom or sign of a serious illness or condition.
But you can’t get treatment if your doctor isn’t aware of your issues. After a lifetime of perfect vision, most adults experience some level of vision loss as they age. Your vision may degrade somewhat between the ages of 41 and 60. But there are other health or work-related conditions that could affect your vision, too. Let your ophthalmologist know about:
- A family history of eye disease
- Chronic conditions, such as high blood pressure or diabetes
- A demanding job that places stress on your eyes or places your eyes in danger
- Certain medications — it’s best to let your doctor know all the medications you’re currently taking
- Other health conditions — such as depression, thyroid disease, high cholesterol or arthritis — especially if you take medications to treat them