Everyone's eyes are a little different
— not just the color, but the way they work and how well they see. Sometimes
all the parts of the eye don't work together the way they should. But eyeglasses or
contact lenses, also called corrective lenses, can help most people see more clearly.
How Eyes Work
The eyeball includes:
(say: KOR-nee-uh), clear tissue that helps the eye focus
the iris, the colored part
the pupil (the black circle in the center of the iris, which is really
an opening in the iris, that lets light enter the eye)
When all of the eyes' parts are working properly, a kid doesn't
have vision problems. You can see because your eyes capture an image like a camera
and send that image to your brain, where it can be interpreted. For instance, if there's
an elephant in front of you, almost instantly, your brain says, "Hey, that's an elephant."
Your eyes need to bend light rays so the image can be focused sharply on your retina.
The better your retina records the image, the more likely that your brain
will interpret the image, and the more likely you will see the image clearly.
Refracting is a big word that means bending light rays. If a person has vision
trouble, it's often a refractive problem. Glasses or contact lenses work so well because
they can correct refractive problems. In other words, they bend the light rays in
a way that lets you see more clearly.
Laser surgery also can correct some vision problems, but it's not allowed for kids
because they're still growing.
Nearsighted and Farsighted — Which Is Which?
Nearsightedness and farsightedness are common refractive problems. It's easy to
get the two confused:
Nearsighted (also called myopia) means someone can see stuff
that's near, like a book, but has trouble seeing stuff that's far away.
Farsighted (also called hyperopia) means someone can see stuff
that's far away clearly, but has more trouble seeing up close (like reading the print
in a book). Some farsightedness in kids is normal because they can focus their eyes
to make up the difference. But some kids are very farsighted and need glasses or contact
In both cases, the image is not properly focused on the retina. With nearsightedness,
the image becomes focused in front of the retina. With farsightedness, the image is
focused behind the retina.
Another refractive problem is called astigmatism (say: uh-STIG-muh-tih-zum).
This means that the cornea is an uneven shape, and it bends the light in different
directions. This can distort what a person sees and make things look blurry.
Glasses or contact lenses correct vision because they allow the eye to focus light
in the right spot on the retina — the spot that produces the clearest image.
Because everyone's eyes are different, a pair of glasses that makes one person see
wonderfully may look terribly blurry to someone else. You know this if you've ever
tried on somebody else's glasses!
If you need glasses or contact lenses, your doctor will write you a prescription.
In this case, a prescription doesn't mean medicine you'll pick up at the drugstore.
A vision prescription is a piece of paper with numbers on it. The people who will
make your glasses for you need these numbers to create lenses that will correct the
way your eye bends light. Remember, the target is right in the center of the retina.
If you're having trouble with your vision, your mom or dad can take you for an
eye exam. This might happen as part of your regular checkup with the doctor.
But you need to see a vision specialist if your parents or your doctor think you
might need glasses. You might see an ophthalmologist, optometrist, or an optician.
What's the difference?
is a medical doctor trained to treat vision problems; this includes prescribing eyeglasses
and contact lenses, but also doing eye surgery for other eye-related problems.
is a licensed professional who specializes in eye exams and in figuring out the right
prescriptions for eyeglasses and contact lenses.
makes or sells eyeglasses and contact lenses according to an ophthalmologist's or
At your eye exam, you'll be asked to read from an eye chart. This is the chart
with letters or numbers in different sizes. You also might be asked to look at
some text up close, like reading from a book. These tests measure how well you see
from close and from far away.
If you need glasses or contact lenses, there's a special gizmo that lets you try
a few different prescriptions until you find the one that gives you the clearest vision.
It's kind of like a big pair of glasses, but a bunch of different lenses can be switched
in and out really quickly. The person doing your eye exam will switch between two
different lenses and say, "Do you like this one or that one?" You say which one looks
clearest. There is no right answer — just what is best for you. Remember, the
idea is that you get the correct prescription so your vision will be top-notch!
The Fun Part
If you're going to get glasses, it's time to pick frames. It can be fun to try
these on. Choose ones that are comfortable and sturdy. But also make sure you like
them — you'll be wearing them a lot!
The lenses themselves can be made of different materials, such as safety glass
or shatterproof plastic (polycarbonate). Because glass tends to be heavy and it may
shatter, most glasses today are made of polycarbonate plastic. If you play sports,
you may want to ask about special eyewear you can wear on the field.
With glasses, you'll also want to find out how to clean them properly. And it helps
if you have a glasses case and put them in it when you're not wearing them. The last
thing you want is to sit on your new glasses. Crunch!
If you're going to get contact lenses, you'll get some
advice from the ophthalmologist or optometrist about which kind will be best for you.
Some are disposable and others need to be cleaned. When you learn which type you're
going to get, you can start becoming an expert in how to wear them safely and keeping
them clean. The most important thing about contact lenses is good hygiene to prevent
infections in your eye.
But the really fun part of new glasses or contact lenses is how well you can see.
They can make your whole world look better!