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-o-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: hi-puh-ro-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 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. Refractive surgery can sometimes also be done on people with farsightedness or astigmatism once their eyes have matured and stopped growing.