Back in 1268, English scientist Roger Bacon had a solution for people whose vision was no longer as sharp as it once was. Bacon said that they could read tiny print by looking through a piece of glass "shaped like the lesser segment of a sphere, with the convex (rounded) side toward the eye."

Fast forward to the 21st century. Glasses, contacts, and eye surgery to correct vision or replace diseased parts of the eye have become common. Even some forms of blindness can be corrected today because of medical advances in eye care.

Even if you're lucky enough to have perfect 20/20 vision, taking care of your eyes and protecting them against injury or infection is important to keeping your peepers perfect.

Vision Basics

One of the best things you can do for your baby blues (or greens, or browns, or hazels, or whatever color your eyes are) is to have them checked by your doctor whenever you have a physical examination. If you're having trouble seeing or if your eyes have been hurting or bothering you, tell a parent so that you can have your eyes examined by an eye specialist.

An ophthalmologist (pronounced: ahf-theh-mah-luh-jist) is a medical doctor who specializes in examining, diagnosing, and treating eyes and eye diseases. An optometrist is not a medical doctor, but has been trained to diagnose and treat many of the same eye conditions as ophthalmologists, except for treatments involving surgery.

It's a good idea to have your eyes checked at least every 2 years or even more frequently if you have a family history of eye problems such as glaucoma or early cataracts.

Common Vision Problems

Have you ever wondered whether there's any truth in some of the stuff you may have been told about how to treat your eyes? For example, you may have been warned that sitting too close to the TV or computer can ruin your eyes. But actually that's wrong. You may also have heard that using a night-light (instead of bright light) to read will cause nearsightedness, but there's no clear scientific evidence to support this idea. You can strain your eyes if you don't have enough light when you read, but it won't ruin your vision.

So what's the cause of many common vision problems? Often, eye shape is the culprit. Someone with perfect 20/20 vision has eyes that are basically round like a baseball. Someone who needs corrective lenses to see usually has eyes that are shaped differently.

Myopia (pronounced: my-oh-pee-uh), or nearsightedness, is one of the most common problems teens have with their eyes. When a teen has myopia, he or she is unable to focus properly on things that are far away. People with myopia have eyes that are a little longer than normal, measuring from the front of the eyeball to the back. This extra length means that light focuses in front of the retina (the part of the eye that receives images and sends them to the brain) instead of on it, and that affects vision. Glasses or contacts can easily correct this problem.

Hyperopia (pronounced: hy-per-oh-pee-uh), or farsightedness, is another problem. People with hyperopia have trouble focusing on things close up because their eyes are too "short" from front to back. In people with hyperopia, light focuses behind the retina instead of on it, causing blurry vision. Someone with significant farsightedness will need glasses to correct his or her vision. But here's an interesting fact: Many babies are born farsighted! Their eyeballs get longer as they grow, and most of them outgrow the condition.

Another condition where the eye is differently shaped is astigmatism. Here, the cornea isn't perfectly round. To be able to see well — either close up or far away — the person needs contact lenses or glasses.

Once people reach 18 and their eyes are fully grown and less likely to change, some people choose to have refractive surgery to correct myopia or hyperopia or astigmatism so they don't have to wear contacts or glasses anymore. Refractive surgery is a procedure — usually done with a laser — that reshapes the eye to change the way light enters it and forms an image, allowing a person to see better.

Dealing With Common Eye Problems and Injuries

The best rule of thumb for when to see an eye specialist if you injure your eyes is "when in doubt, check it out!"

• If you have a red eye, pain in an eye that doesn't go away within a short period of time, or at any time have had changes in your vision, then it's time to have your eyes checked.
• If you get any small foreign objects in your eye, such as sand or sawdust or metal shavings, don't rub it. Flush your eye for several minutes with lukewarm water (it may be easiest to do this in the shower). If it still feels as though there is something in your eye, then be sure to see an eye specialist.
• If you've been hit in the eye and it looks strange or appears to be bleeding, or if you have changes in or lose your vision, go to a hospital emergency department right away to be checked out.

One of the most common eye injuries for teens is a scratched cornea, which is often related to wearing contact lenses or playing sports. With a scratched cornea, it may feel like something is in your eye when there's really nothing there. Your eye may get red and irritated, produce lots of tears, and be overly sensitive to light.

If you think you have any kind of eye injury and you wear contact lenses, stop wearing your contacts until you see an eye specialist. Wearing contact lenses if you have an eye injury could damage your eyes more or cause an infection to develop. Don't worry — if your cornea is scratched, it usually will heal quickly and may require a week or two of medicated eye drops and not wearing your contacts. You may hate wearing your old glasses, but it's just for a little while — and it beats permanently damaging your eyes!

Caring for Your Eyes

Just as you wear a seat belt to protect yourself when you're in a car, it's wise to protect your eyes before something happens to them.

Wearing sunglasses is high on the list of ways you can care for your vision. Buy a pair of sunglasses with ultraviolet (UV) protection to use whenever you're in the sun. UV light causes long-term damage to the inner structures of the eye, but wearing sunglasses whenever you're in the sun can help prevent conditions such as cataracts and macular degeneration.

A cataract is an eye condition in which the lens of the eye becomes clouded, impairing vision. Macular degeneration is an eye disease in which the macula, a structure within the eye that allows you to see, gradually deteriorates, leading to decreased vision or blindness. (Need one more reason not to smoke? Smoking puts you at greater risk for developing macular degeneration.)

You can also care for your eyes by putting on protective eyewear whenever you play sports like racquetball or when you're doing projects in shop class or the science lab. It only takes a second for something to hit an unprotected eye and cause serious damage. And avoid being near fireworks that could explode and harm your eyes. Why take chances with your vision?

Although steering clear of fireworks probably seems like an obvious way to protect your eyes, you may not think about protecting them around the house. Yet something you might do every day — staring at a computer screen for a long time — can strain your eyes. That's because most people blink about 10 times per minute. But when you stare, your blink rate can go down to two or three times per minute. The best thing you can do is to blink more! It also helps to change your focus frequently. Look at something across the room for a few moments and then go back to looking at the computer screen.

If your eyes feel dry and irritated when you use the computer, use artificial tears. Don't use products that remove the red from your eyes, though, because they may contain a chemical that eliminates redness temporarily but actually makes your eyes look worse later.

You should take special care of your eyes if you have a medical condition such as diabetes or juvenile rheumatoid arthritis because these conditions put you at an increased risk of developing serious eye disease. Be sure to see your doctor at least once a year if you have any medical condition that can affect your eyes. Depending on your situation, your doctor may need to check your eyes as often as every 3 months.

Preventing Eye Infections

You can also protect your eyes by preventing infections that could harm them. Conjunctivitis, also called pinkeye, is an eye infection that can be caused by a virus, bacteria, an allergic reaction, a chemical, or an irritant (something that gets in the eye).

Conjunctivitis caused by germs like viruses and bacteria can easily pass from person to person. After you shake hands with someone who has a bad cold and pinkeye, for instance, you could spread the infection to your own eye by touching it with your hand.

To avoid spreading the germs that can cause eye infections:

• Don't share eye makeup or drops with anyone else.
• Don't touch the tip of a bottle of eye drops with your hands or your eyes because that can contaminate it with germs.
• Never put contact lenses in your mouth to wet them. Many bacteria and viruses — maybe even the virus that causes cold sores — are present in your mouth and could easily spread to your eyes.
• Wash your hands regularly!

Glasses and Contacts

If you need glasses or contact lenses, you can follow a few tips for the best results. When you pick out glasses, remember as a general rule that smaller frames will probably suit you better. The larger the frame, the more distortion you'll have, and you may not be able to see as well.

If you get contact lenses, follow your doctor's orders exactly when it comes to cleaning them, how many hours you can safely wear them, and when you should replace them. If you don't, you could develop serious infections or ulcers in your eye that are painful, difficult to treat, and may need months of medication or even surgery.

Eyes and vision are something no one wants to be without. To keep them working for you for many years to come, protect them now and take the best care of them that you can.

Reviewed by: Jonathan H. Salvin, MD
Date reviewed: July 2011